docs(notes): record that no test tier can see a hover media query

Both browser tiers are blind to `(hover: hover)` gating, in different
ways and without failing: CDP media emulation does not reach ui-test's
iframe, and e2e's phone specs reach phone width with setViewportSize,
which changes no media feature but width. Written down with what does
work — a device-descriptor context — because the next person to gate an
affordance this way will otherwise re-derive it, and the tempting
conclusion from a green suite is that the gate is covered.

.planning/NOTES.md

@@ -3664,3 +3664,35 @@ knowing before someone "fixes" it as broken: sampled from screenshots at
 900×600, the main panel's background goes 33,37,41 → 18,20,23 and a
 row's text 242 → 133. It covers the content area only — not the sidebar
 or the transport — because the queue is not modal.
+
+## No test tier can see a `hover:` media query (measured 2026-08-19)
+
+Gating an affordance on `(hover: hover) and (pointer: fine)` — #68's fix
+for the play button that flashed on a long-press — is invisible to both
+browser tiers, in *different* ways, and neither of them fails.
+
+- **`make ui-test`**: CDP's `Emulation.setEmulatedMedia` with a `hover`
+  feature does not reach the tier's iframe. The call succeeds and
+  `matchMedia('(hover: hover)')` still answers `true` afterwards. So
+  there is no way to render a component as a phone would and read the
+  computed style.
+- **`make e2e`**: both projects are desktop (`Desktop Chrome`,
+  `Desktop Safari`), and the phone specs reach phone *width* with
+  `setViewportSize`, which changes no media feature but `width`. So the
+  phone specs run with `hover: hover` and the gate is never exercised.
+
+What does work, and what the fix was verified with, is a second browser
+context under a device descriptor: `chromium.newContext(devices['Pixel
+5'])` reports `hover=false pointer:fine=false` and the button computes
+`display: none`, against `flex` at 1440px. That is a one-off script, not
+a spec — `isMobile` is Chromium-only, so it cannot become an e2e project
+without losing the WebKit half.
+
+`hover-affordance.test.ts` therefore asserts the *parsed stylesheet* —
+that the reveal rule sits inside the media query — which catches the
+regression that actually threatens it: someone hoisting the rule back out
+as a tidy-up, a change nothing on a desktop renders differently.
+
+Related: a width-gated decision **is** testable at both tiers, which is
+why #61's phone mini player is a `matchMedia` stub in the component test
+and needs nothing special.

CLAUDE.md

@@ -2369,6 +2369,23 @@ Pre-commit hooks verify generated code is fresh — always run `make generate` a
   mistyped `feat` ships a minor version. `make release-dry` answers "what
   would this merge release" without pushing.
 
+  **The analyzer reads the type and ignores the scope, so a CI-only change
+  is `ci:` and never `fix(ci):`.** The scope is decoration; `fix` is a
+  patch whatever is in the brackets. Two commits touching nothing but
+  `.gitea/workflows/unclaim.yml` were written `fix(ci):` and cut `v0.2.1`
+  and `v0.2.2` — real releases, published to Arch, Homebrew and the APK
+  registry, containing no user-facing change. They were left in place
+  rather than deleted, because a version that vanishes is worse for
+  whoever pulled it than one that turns out to be empty.
+
+  **The blast radius is bigger than the version number**, which is what
+  makes this worth a paragraph. A merge to `main` starts two workflows;
+  if `release.yml` then pushes a tag, that tag push starts **four more**
+  (`arch-package`, `homebrew-formula`, `android-apk`, `desktop-assets`) —
+  on a runner with capacity 1, where the APK build alone is tens of
+  minutes. `make release-dry` before merging is how you find out, and it
+  is cheaper than every one of those.
+
   **`@semantic-release/github` is not in that config and must not be.**
   Gitea's API is `/api/v1` and is not GitHub's surface, so
   `@semantic-release/exec` calls `scripts/gitea-release.sh` instead — one

backend/explore/prune_test.go

@@ -82,6 +82,100 @@ func TestPruneStaleLocalCrossReferences(t *testing.T) {
 	}
 }
 
+// TestPruneClearsInLibraryWithNoLocalID covers the fixed point: a row
+// carrying in_library with a NULL local_*_id.  The upsert's conflict
+// clause is `in_library = MAX(in_library, excluded.in_library)`, so it
+// can only ever raise the flag, and this pass used to be gated on the id
+// being present — which meant nothing in the app could clear such a row,
+// ever.  It is asserted for all three entity types because the gate was
+// written once and used three times, so a fix applied to one is a fix
+// that looks complete.
+//
+// The rows are seeded with raw SQL rather than through seedIndexResult
+// deliberately: upsertBatch writes a zero LocalArtistID as literal 0,
+// not NULL, and 0 satisfies `IS NOT NULL` — so the old gate already
+// caught that shape and a fixture built through the upsert cannot
+// reproduce this at all.  NULL is what the artifact importer and any
+// older writer leave behind, the column being nullable with no default.
+func TestPruneClearsInLibraryWithNoLocalID(t *testing.T) {
+	t.Parallel()
+
+	db := database.NewTestDB(t)
+	si := NewSearchIndex(db, nil, nil, slog.Default())
+
+	// A genuinely owned artist, to prove the wider gate does not simply
+	// clear everything it now looks at.
+	database.InsertTestTrack(t, db, database.TestTrack{
+		FilePath: "/music/owned.mp3",
+		Artist:   "Owned",
+	})
+
+	artist, err := db.Queries.GetArtistByName(t.Context(), "Owned")
+	if err != nil {
+		t.Fatalf("read seeded artist: %v", err)
+	}
+
+	seedIndexResult(t, db, SearchIndexResult{
+		EntityType:    EntityArtist,
+		MBID:          testMBID("owned"),
+		Title:         "Owned",
+		ArtistName:    "Owned",
+		ArtistMBID:    testMBID("owned"),
+		InLibrary:     true,
+		LocalArtistID: artist.ID,
+	})
+
+	orphans := []struct {
+		name       string
+		entityType string
+		mbid       string
+	}{
+		{"artist", EntityArtist, "orphan-artist"},
+		{"release group", EntityReleaseGroup, "orphan-release-group"},
+		{"recording", EntityRecording, "orphan-recording"},
+	}
+
+	for _, o := range orphans {
+		if _, err := db.ExecContext(
+			`INSERT INTO explore_index
+			     (entity_type, mbid, title, artist_name, artist_mbid,
+			      in_library,
+			      local_artist_id, local_release_group_id, local_recording_id)
+			 VALUES (?, ?, ?, ?, ?, 1, ?, ?, ?)`,
+			dbEntityType(o.entityType), dbMBID(testMBID(o.mbid)), o.name, o.name,
+			dbMBID(testMBID(o.mbid)),
+			nil, nil, nil,
+		); err != nil {
+			t.Fatalf("seed %s orphan: %v", o.name, err)
+		}
+	}
+
+	si.pruneStaleLocalCrossReferences()
+
+	inLibrary := func(t *testing.T, mbid string) int {
+		t.Helper()
+
+		var flag int
+		if err := db.QueryRowWriter(
+			"SELECT in_library FROM explore_index WHERE mbid = ?", dbMBID(mbid),
+		).Scan(&flag); err != nil {
+			t.Fatalf("read in_library for %q: %v", mbid, err)
+		}
+
+		return flag
+	}
+
+	for _, o := range orphans {
+		if got := inLibrary(t, testMBID(o.mbid)); got != 0 {
+			t.Errorf("%s with a NULL local id: in_library = %d, want 0", o.name, got)
+		}
+	}
+
+	if got := inLibrary(t, testMBID("owned")); got != 1 {
+		t.Errorf("owned artist: in_library = %d, want 1 (it still has a file)", got)
+	}
+}
+
 // TestUnenrichedLibraryArtistMBIDs_OrdersByOwnedTrackCount verifies the
 // backfill queue prioritizes artists by how many tracks the user actually
 // owns, not by how many duplicate-mbid artist rows happen to exist (the

backend/explore/searchindex.go

@@ -2562,6 +2562,19 @@ func (si *SearchIndex) PopulateLocalCrossReferences() {
 // The row itself is left in place (it may still be part of the shipped
 // catalog, just no longer owned) — only the "this is mine" bookkeeping
 // is cleared.
+//
+// It is gated on the flag *or* the id, not on the id alone.  Gated on
+// the id, `in_library = 1 AND local_*_id IS NULL` is a fixed point: the
+// upsert can only ever raise the flag and this pass skipped such a row
+// by construction, so nothing in the app could clear it — a row claiming
+// to be owned, permanently, with no local row to check the claim
+// against.  Nothing in the tree writes that shape today
+// (collectLibraryEntities sets both together), which is exactly why it
+// is worth closing now: the exposure is a database written by an older
+// version, and the next writer that sets the flag without an id, which
+// nothing structurally prevents.  A NULL id fails the existence test on
+// its own, so the wider gate needs no second clause to say what "not
+// owned" means.
 func (si *SearchIndex) pruneStaleLocalCrossReferences() {
 	type prune struct {
 		entityType string
@@ -2594,7 +2607,8 @@ func (si *SearchIndex) pruneStaleLocalCrossReferences() {
 		result, err := si.db.ExecContext(
 			`UPDATE explore_index
 			 SET in_library = 0, `+p.column+` = NULL
-			 WHERE entity_type = ? AND `+p.column+` IS NOT NULL
+			 WHERE entity_type = ?
+			   AND (`+p.column+` IS NOT NULL OR in_library = 1)
 			   AND NOT EXISTS (`+p.exists+`)`,
 			dbEntityType(p.entityType),
 		)

backend/player/buffered_stall_test.go

@@ -0,0 +1,188 @@
+package player
+
+import (
+	"errors"
+	"testing"
+	"time"
+
+	"github.com/gopxl/beep/v2"
+)
+
+// errTestDecode stands in for a decoder blowing up mid-track.
+var errTestDecode = errors.New("decode blew up")
+
+// stalledStreamer never produces a sample and never reports
+// end-of-stream: (0, true), forever. A damaged file that decodes to
+// nothing looks like this, and so does any source whose producer has
+// quietly stopped.
+type stalledStreamer struct{}
+
+func (stalledStreamer) Stream(_ [][2]float64) (int, bool) { return 0, true }
+func (stalledStreamer) Err() error                        { return nil }
+
+// failingStreamer produces n good samples and then fails, which is
+// what a decode error mid-track looks like: the same (0, false) a
+// finished track returns, distinguishable only by Err.
+type failingStreamer struct {
+	remaining int
+	err       error
+}
+
+func (f *failingStreamer) Stream(samples [][2]float64) (int, bool) {
+	if f.remaining <= 0 {
+		return 0, false
+	}
+
+	n := min(len(samples), f.remaining)
+
+	for i := range n {
+		samples[i] = [2]float64{1, 1}
+	}
+
+	f.remaining -= n
+
+	return n, true
+}
+
+func (f *failingStreamer) Err() error { return f.err }
+
+// drainUntilEnd calls Stream until it reports end-of-stream, or gives
+// up. It returns whether the stream ended.
+//
+// The give-up bound is wall clock rather than a call count: the stall
+// budget is a duration, so a tight loop has to actually wait it out.
+func drainUntilEnd(bs *BufferedStreamer, within time.Duration) bool {
+	buf := make([][2]float64, 512)
+	deadline := time.Now().Add(within)
+
+	for time.Now().Before(deadline) {
+		if _, ok := bs.Stream(buf); !ok {
+			return true
+		}
+
+		time.Sleep(time.Millisecond)
+	}
+
+	return false
+}
+
+// A source that stops producing without ever ending is the fault this
+// whole file exists for: Stream used to answer with silence and ok
+// forever, so the chain never ended, the player stayed in Playing
+// with the button showing pause, and the decoder's position never
+// moved -- a frozen seek bar over a track that was not playing.
+func TestAStalledSourceEndsTheStream(t *testing.T) {
+	bs := NewBufferedStreamer(stalledStreamer{}, 2048)
+	defer bs.Close()
+
+	if !drainUntilEnd(bs, maxStarvedDuration+2*time.Second) {
+		t.Fatal(
+			"a stalled source never ended the stream: the player " +
+				"would sit in Playing with a frozen position",
+		)
+	}
+
+	if !errors.Is(bs.Err(), errSourceStalled) {
+		t.Fatalf(
+			"expected the stall to be reported, got %v", bs.Err(),
+		)
+	}
+}
+
+// Close is the other exit that used to leave `done` false, with the
+// same consequence: the ring drains and every call after it is
+// silence that claims to be audio.
+func TestClosingEndsTheStream(t *testing.T) {
+	bs := NewBufferedStreamer(finiteStreamer(1<<20), 2048)
+
+	// Let the read-ahead fill something, so this exercises the drain
+	// after Close rather than a buffer that was empty anyway.
+	time.Sleep(20 * time.Millisecond)
+	bs.Close()
+
+	if !drainUntilEnd(bs, 2*time.Second) {
+		t.Fatal("a closed streamer never reported end-of-stream")
+	}
+}
+
+// A source that fails is not a source that finished, and only Err
+// tells them apart. Before this, the player reported a mid-track
+// decode failure to the queue as a natural end, so the queue
+// auto-advanced in silence and counted the broken track as played.
+func TestAFailedSourceReportsItsError(t *testing.T) {
+	src := &failingStreamer{remaining: 4096, err: errTestDecode}
+
+	bs := NewBufferedStreamer(src, 2048)
+	defer bs.Close()
+
+	if !drainUntilEnd(bs, 2*time.Second) {
+		t.Fatal("a failing source never reported end-of-stream")
+	}
+
+	if !errors.Is(bs.Err(), errTestDecode) {
+		t.Fatalf(
+			"expected the source's error to survive, got %v",
+			bs.Err(),
+		)
+	}
+}
+
+// The ordinary case has to keep working: a source that ends cleanly
+// ends with no error, or every finished track would be reported as a
+// failure and skipped.
+func TestADrainedSourceReportsNoError(t *testing.T) {
+	bs := NewBufferedStreamer(finiteStreamer(4096), 2048)
+	defer bs.Close()
+
+	if !drainUntilEnd(bs, 2*time.Second) {
+		t.Fatal("a finite source never reported end-of-stream")
+	}
+
+	if bs.Err() != nil {
+		t.Fatalf(
+			"a track that finished normally reported %v", bs.Err(),
+		)
+	}
+}
+
+// A slow source is exactly what the read-ahead exists to absorb, so
+// underruns must not be charged cumulatively -- otherwise a file on a
+// slow disk ends itself partway through.
+func TestUnderrunsDoNotAccumulateAcrossASlowSource(t *testing.T) {
+	const total = 8192
+
+	src := &slowStreamer{
+		inner: finiteStreamer(total),
+		delay: 2 * time.Millisecond,
+	}
+
+	bs := NewBufferedStreamer(src, 1024)
+	defer bs.Close()
+
+	buf := make([][2]float64, 256)
+	got := 0
+
+	for {
+		n, ok := bs.Stream(buf)
+		if !ok {
+			break
+		}
+
+		for i := range n {
+			if buf[i][0] != 0 {
+				got++
+			}
+		}
+	}
+
+	if got != total {
+		t.Fatalf(
+			"a slow but healthy source was cut short: got %d of %d "+
+				"samples",
+			got, total,
+		)
+	}
+}
+
+// beep.Streamer is what the player wraps; keep the type honest.
+var _ beep.Streamer = (*BufferedStreamer)(nil)

backend/player/buffered_streamer.go

@@ -1,6 +1,7 @@
 package player
 
 import (
+	"errors"
 	"sync"
 	"time"
 
@@ -34,8 +35,45 @@ type BufferedStreamer struct {
 	done    bool
 	err     error
 	closed  chan struct{}
+
+	// starved counts consecutive Stream calls served with silence
+	// because the ring was empty, and starvedSince is when that run
+	// began.  An underrun is legitimate for a moment -- that is what
+	// the read-ahead exists to absorb -- but it is not legitimate
+	// forever, and "forever" is indistinguishable from healthy
+	// playback everywhere above this type: the chain never ends, so
+	// the player stays in Playing with the button showing pause, and
+	// the decoder's position never moves, so the 1 Hz report pins the
+	// seek bar and suppresses its interpolation.
+	starved      int
+	starvedSince time.Time
 }
 
+// The silence fill is bounded by both a duration and a run of calls,
+// and it needs both.
+//
+// Duration alone is the real measure -- the speaker paces itself, so
+// wall clock is what says whether the source has actually stopped --
+// but a caller draining in a tight loop (a test, a decode-to-buffer)
+// makes hundreds of calls in microseconds and would trip nothing.
+// A call count alone is the opposite failure: the same tight loop
+// spends the whole budget before the read-ahead goroutine has been
+// scheduled once, and ends a perfectly good stream at sample zero.
+//
+// The duration is longer than the 2 s read-ahead it is there to
+// outlast, and the count is short enough that the speaker (~200 ms a
+// call) reaches it well inside that.
+const (
+	maxStarvedDuration = 3 * time.Second
+	minStarvedCalls    = 8
+)
+
+// errSourceStalled is returned by Err when the source stopped
+// producing samples without ever reporting end-of-stream.
+var errSourceStalled = errors.New(
+	"audio source stopped producing samples",
+)
+
 // NewBufferedStreamer creates a BufferedStreamer that pre-fills
 // bufferSize samples from source via a background goroutine.
 // A typical bufferSize is 2× the sample rate (~2 seconds of audio).
@@ -54,8 +92,24 @@ func NewBufferedStreamer(
 	return bs
 }
 
+// finish marks the stream ended, recording err as the reason when
+// there is one.  Every exit from readAhead goes through it: an exit
+// that leaves done false strands Stream in its underrun branch,
+// where it returns silence and ok forever.
+func (bs *BufferedStreamer) finish(err error) {
+	bs.mu.Lock()
+	defer bs.mu.Unlock()
+
+	bs.done = true
+
+	if err != nil && bs.err == nil {
+		bs.err = err
+	}
+}
+
 // readAhead continuously reads from the source into the ring buffer
 // until the source is drained, an error occurs, or Close is called.
+// It always marks the stream done on the way out.
 func (bs *BufferedStreamer) readAhead() {
 	// Temporary buffer for reading from source outside the lock.
 	// 512 samples per chunk keeps the critical section short.
@@ -63,6 +117,13 @@ func (bs *BufferedStreamer) readAhead() {
 
 	tmp := make([][2]float64, chunkSize)
 
+	// Every exit marks the stream done.  An exit that does not is what
+	// stranded Stream in its underrun branch, returning silence and ok
+	// for the rest of the process's life.
+	var exitErr error
+
+	defer func() { bs.finish(exitErr) }()
+
 	for {
 		// Check if closed.
 		select {
@@ -72,6 +133,15 @@ func (bs *BufferedStreamer) readAhead() {
 		}
 
 		bs.mu.Lock()
+
+		// Stream gave up waiting for us.  Nothing downstream is
+		// listening any more, so filling the ring is work for nobody.
+		if bs.done {
+			bs.mu.Unlock()
+
+			return
+		}
+
 		space := len(bs.ring) - bs.count
 
 		if space == 0 {
@@ -115,14 +185,12 @@ func (bs *BufferedStreamer) readAhead() {
 		}
 
 		if !ok {
-			bs.mu.Lock()
+			// A drained source and a failed one both land here and are
-			bs.done = true
+			// not the same event: one is a track that ended, the other
-
+			// is a track that broke.  Err is what tells them apart, and
-			if srcErr := bs.source.Err(); srcErr != nil {
+			// it is why the player must ask before treating this as a
-				bs.err = srcErr
+			// natural finish.
-			}
+			exitErr = bs.source.Err()
-
-			bs.mu.Unlock()
 
 			return
 		}
@@ -154,7 +222,27 @@ func (bs *BufferedStreamer) Stream(
 	}
 
 	if bs.count == 0 {
-		// Buffer temporarily empty — fill with silence.
+		// The read-ahead has not caught up.  Silence buys it time --
+		// but only for a bounded stretch, because "forever" is
+		// reported upward as healthy playback and there is no watchdog
+		// above this to notice otherwise.
+		bs.starved++
+
+		if bs.starvedSince.IsZero() {
+			bs.starvedSince = time.Now()
+		}
+
+		if bs.starved >= minStarvedCalls &&
+			time.Since(bs.starvedSince) > maxStarvedDuration {
+			bs.done = true
+
+			if bs.err == nil {
+				bs.err = errSourceStalled
+			}
+
+			return 0, false
+		}
+
 		for i := range samples {
 			samples[i] = [2]float64{}
 		}
@@ -162,6 +250,9 @@ func (bs *BufferedStreamer) Stream(
 		return len(samples), true
 	}
 
+	// Samples arrived, so whatever the stall was, it is over.
+	bs.resetStarvationLocked()
+
 	// Copy available samples from ring buffer.
 	n := len(samples)
 	if n > bs.count {
@@ -197,6 +288,19 @@ func (bs *BufferedStreamer) Flush() {
 	bs.readPos = 0
 	bs.writPos = 0
 	bs.count = 0
+
+	// A seek empties the ring on purpose, and the refill that follows
+	// is exactly the stall the budget exists to tolerate.  Charging it
+	// against a budget the previous underrun already spent would end
+	// the track on a seek near the end of a slow file.
+	bs.resetStarvationLocked()
+}
+
+// resetStarvationLocked forgets an underrun run.  Must be called with
+// bs.mu held.
+func (bs *BufferedStreamer) resetStarvationLocked() {
+	bs.starved = 0
+	bs.starvedSince = time.Time{}
 }
 
 // LockSource blocks the read-ahead goroutine from touching the

backend/player/loadstate_test.go

@@ -0,0 +1,213 @@
+package player
+
+import (
+	"log/slog"
+	"testing"
+	"time"
+
+	"github.com/wailsapp/wails/v3/pkg/application"
+
+	"yellowjacket/backend/events"
+	"yellowjacket/internal/testfixtures"
+)
+
+// fixtureSampleRate is what cmd/gentestdata writes (audio.go).  It is
+// deliberately not the speaker rate, which is what lets these tests
+// tell the decoder's format from the player's default.
+const fixtureSampleRate = 22050
+
+// newTestPlayer is a player with a context and no database, so the
+// track-metadata lookup cannot succeed.
+func newTestPlayer(t *testing.T) *Player {
+	t.Helper()
+
+	p := NewPlayer(slog.Default(), nil)
+	rec := events.NewRecorder()
+
+	_ = p.ServiceStartup(
+		events.WithSink(t.Context(), rec),
+		application.ServiceOptions{},
+	)
+
+	return p
+}
+
+// loadFileLocked needs no speaker: it decodes, builds the chain and
+// registers it paused. speaker.Play on an uninitialised device is
+// what the integration guard elsewhere is about, so these assert on
+// the state the load computed rather than on playback.
+
+// p.format used to be assigned once, in the constructor, to the
+// *speaker's* rate -- so it claimed 44.1 kHz for every file ever
+// loaded. Play()'s replay-after-finish path resamples from it, so a
+// finished track played again was resampled from a rate the decoder
+// never produced: audibly the wrong speed and pitch, and wrong
+// length and position arithmetic with it.
+//
+// The fixtures are 22050 Hz, which is exactly the point -- any of
+// them disagrees with the speaker rate.
+func TestLoadRecordsTheDecodersOwnFormat(t *testing.T) {
+	m := testfixtures.Load(t)
+	path := m.Case(t, testfixtures.CaseCoverDedup)[0]
+
+	p := newTestPlayer(t)
+
+	if got := p.format.SampleRate; got != speakerSampleRate {
+		t.Fatalf(
+			"precondition: a fresh player should hold the speaker "+
+				"rate, got %d",
+			got,
+		)
+	}
+
+	if err := p.LoadFile(path); err != nil {
+		t.Fatalf("LoadFile(%s): %v", path, err)
+	}
+
+	if p.format.SampleRate == speakerSampleRate {
+		t.Fatalf(
+			"p.format still holds the speaker rate (%d) after "+
+				"loading a %d Hz file: the replay path would "+
+				"resample from the wrong rate",
+			speakerSampleRate, fixtureSampleRate,
+		)
+	}
+
+	if got := int(p.format.SampleRate); got != fixtureSampleRate {
+		t.Errorf(
+			"expected the decoder's rate %d, got %d",
+			fixtureSampleRate, got,
+		)
+	}
+}
+
+// trackLengthMs is written only when the database has a row for the
+// file and cleared only by UnloadTrack, so a track with no row used
+// to inherit whatever the last track's duration was -- and every
+// position report is scaled by it, so the whole seek bar was then
+// reporting one track's progress on another track's scale.
+//
+// There is no database here, so the lookup cannot succeed: exactly
+// the case that used to inherit.
+func TestLoadDoesNotInheritThePreviousTracksDuration(t *testing.T) {
+	m := testfixtures.Load(t)
+	path := m.Case(t, testfixtures.CaseCoverDedup)[0]
+
+	p := newTestPlayer(t)
+
+	// Stand in for a previous track whose duration was resolved.
+	p.trackLengthMs = 9_999_000
+
+	if err := p.LoadFile(path); err != nil {
+		t.Fatalf("LoadFile(%s): %v", path, err)
+	}
+
+	if p.trackLengthMs == 9_999_000 {
+		t.Fatal(
+			"the previous track's duration survived the load: every " +
+				"position report for this track would be scaled by it",
+		)
+	}
+}
+
+// A new chain supersedes the old one's pending finished callback.
+// Without this, a callback that queued for p.mu behind a LoadFile
+// woke up and rewound, stopped and auto-advanced the *new* track.
+func TestANewChainSupersedesTheOldFinishedCallback(t *testing.T) {
+	m := testfixtures.Load(t)
+	paths := m.Case(t, testfixtures.CaseCoverDedup)
+
+	if len(paths) < 2 {
+		t.Skip("need two fixture tracks")
+	}
+
+	p := newTestPlayer(t)
+
+	if err := p.LoadFile(paths[0]); err != nil {
+		t.Fatalf("LoadFile(%s): %v", paths[0], err)
+	}
+
+	stale := p.chainID
+
+	if err := p.LoadFile(paths[1]); err != nil {
+		t.Fatalf("LoadFile(%s): %v", paths[1], err)
+	}
+
+	if p.chainID == stale {
+		t.Fatal("loading a second file did not supersede the chain")
+	}
+
+	called := false
+
+	p.SetPlaybackFinishedHandler(func(error) { called = true })
+
+	// The first track's callback, arriving late.
+	p.onPlaybackFinished(stale, nil)
+
+	if called {
+		t.Error(
+			"a superseded chain's callback drove auto-advance: the " +
+				"track that is loaded now would be skipped",
+		)
+	}
+
+	if p.state == Stopped {
+		t.Error(
+			"a superseded chain's callback stopped the current track",
+		)
+	}
+}
+
+// The decoder is read by the read-ahead goroutine and by every
+// position emit, and those used to be guarded by different mutexes:
+// the read by srcMu, the position by the speaker lock, which
+// read-ahead never takes. Under -race this failed on the emit that
+// LoadFile itself makes.
+//
+// It needs the read-ahead goroutine to actually be running, so it
+// keeps asking for the position for long enough to overlap it.
+func TestPositionReadsDoNotRaceTheReadAhead(t *testing.T) {
+	m := testfixtures.Load(t)
+	path := m.Case(t, testfixtures.CaseFLACAlbum)[0]
+
+	p := newTestPlayer(t)
+
+	if err := p.LoadFile(path); err != nil {
+		t.Fatalf("LoadFile(%s): %v", path, err)
+	}
+
+	for range 200 {
+		if _, err := p.CurrentPositionSeconds(); err != nil {
+			t.Fatalf("CurrentPositionSeconds: %v", err)
+		}
+	}
+}
+
+// Seeking emits the landing position, and that emit reads the
+// decoder -- so the source lock the seek holds must be released
+// before it. A reentrant take here is a deadlock, not a failure,
+// which is why this test exists rather than a comment.
+func TestSeekEmitsWithoutDeadlocking(t *testing.T) {
+	m := testfixtures.Load(t)
+	path := m.Case(t, testfixtures.CaseFLACAlbum)[0]
+
+	p := newTestPlayer(t)
+
+	if err := p.LoadFile(path); err != nil {
+		t.Fatalf("LoadFile(%s): %v", path, err)
+	}
+
+	done := make(chan struct{})
+
+	go func() {
+		defer close(done)
+
+		_ = p.Seek(1)
+	}()
+
+	select {
+	case <-done:
+	case <-time.After(10 * time.Second):
+		t.Fatal("Seek deadlocked: the position emit re-took the source lock")
+	}
+}

backend/player/player.go

@@ -52,9 +52,17 @@ type Player struct {
 	control                 *beep.Ctrl
 	volume                  *effects.Volume
 	speakerStreamer         beep.Streamer
-	playbackFinishedHandler func()
+	playbackFinishedHandler func(error)
 	trackChangeID           uint64
-	mediaControls           mediacontrols.Handler
+
+	// chainID identifies the streamer chain currently registered with
+	// the speaker.  updateStreamers bumps it, and the finished
+	// callback carries the value it was registered with, so a callback
+	// that queued for p.mu behind a LoadFile can tell that the player
+	// has moved on and return rather than rewinding somebody else's
+	// track.
+	chainID       uint64
+	mediaControls mediacontrols.Handler
 
 	// duckAmount is the attenuation currently applied on top of the
 	// user's volume, in the same base-2 exponent effects.Volume uses.
@@ -180,11 +188,18 @@ func (p *Player) InitSpeaker() error {
 }
 
 // SetPlaybackFinishedHandler sets a callback invoked when a track
-// finishes naturally. This allows the queue to drive auto-advance
+// stops streaming. This allows the queue to drive auto-advance
 // without circular imports.
 //
+// The error says *why* the track stopped: nil for a track that
+// reached its end, non-nil for one that broke partway through.  Both
+// arrive here because both look identical to the speaker, and only
+// the queue holds the metadata a PlaybackFailed needs -- but they are
+// not the same event, and reporting a decode failure as a natural
+// finish is how a broken file used to auto-advance in silence.
+//
 //wails:ignore // internal wiring, not part of the app's IPC surface.
-func (p *Player) SetPlaybackFinishedHandler(handler func()) {
+func (p *Player) SetPlaybackFinishedHandler(handler func(error)) {
 	p.mu.Lock()
 	defer p.mu.Unlock()
 
@@ -424,6 +439,19 @@ func (p *Player) updateStreamers(
 	newBaseStreamer beep.StreamSeeker,
 	sr beep.SampleRate,
 ) error {
+	// A new chain supersedes the old one, so any finished callback the
+	// old one still owes is stale from here on.
+	p.chainID++
+
+	// The previous read-ahead goroutine reads the same decoder this
+	// one is about to, under its own srcMu -- two goroutines, two
+	// mutexes, one decoder that is not safe for concurrent use.  The
+	// replay-after-finish path rebuilds from p.seeker without going
+	// through LoadFile, which is where that pair could meet.
+	if p.buffered != nil {
+		p.buffered.Close()
+	}
+
 	// set base streamer
 	p.baseStreamer = newBaseStreamer
 	p.seeker = newBaseStreamer
@@ -474,23 +502,57 @@ func (p *Player) startPaused() {
 	p.control.Paused = true
 	speaker.Unlock()
 
+	// Captured, not read at callback time: by then p.chainID names
+	// whatever is loaded *now*, which is the thing the guard exists to
+	// distinguish this chain from.
+	chainID := p.chainID
+	buffered := p.buffered
+
 	// The beep.Callback runs with the speaker mutex held, so we
 	// dispatch to a goroutine that can safely acquire p.mu.
 	speaker.Play(beep.Seq(
 		p.speakerStreamer,
 		beep.Callback(func() {
-			go p.onPlaybackFinished()
+			// Asked here rather than under p.mu: this is the chain that
+			// just ended, and by the time the goroutine holds the lock
+			// p.buffered may be a different one.
+			var err error
+			if buffered != nil {
+				err = buffered.Err()
+			}
+
+			go p.onPlaybackFinished(chainID, err)
 		}),
 	))
 
 	p.state = Paused
 }
 
-// onPlaybackFinished handles the natural end of a track. It is
+// onPlaybackFinished handles a track that stopped streaming, whether
-// called on a new goroutine from the beep callback (which holds
+// it ended or broke. It is called on a new goroutine from the beep
-// the speaker lock) so that it can safely acquire p.mu.
+// callback (which holds the speaker lock) so that it can safely
-func (p *Player) onPlaybackFinished() {
+// acquire p.mu.
+//
+// chainID names the streamer chain the callback fired for and srcErr
+// says why it stopped.
+func (p *Player) onPlaybackFinished(chainID uint64, srcErr error) {
 	p.mu.Lock()
+
+	// The player has moved on while this callback queued for the lock
+	// -- a user pressing Next during the last second of a track is
+	// enough. Everything below is about the *current* track: rewinding
+	// the decoder, saying playback stopped, asking the queue to
+	// advance. Doing any of it now would do it to the wrong track.
+	if chainID != p.chainID {
+		p.mu.Unlock()
+		p.logger.Debug(
+			"Ignoring finished callback for a superseded chain",
+			"chain", chainID, "current", p.chainID,
+		)
+
+		return
+	}
+
 	p.state = Stopped
 	handler := p.playbackFinishedHandler
 	mc := p.mediaControls
@@ -501,10 +563,11 @@ func (p *Player) onPlaybackFinished() {
 	// the Stopped state anyway, so this only moves the decoder.
 	p.rewindLocked()
 	p.emitPositionLocked()
-	p.mu.Unlock()
 
-	// Emit Wails events outside the lock — these are non-blocking
+	// Emitted under p.mu, like every other transition in this file.
-	// calls that don't need player state.
+	// Outside it, a Play() taking the lock in the gap emits `playing`
+	// first and this stale `stopped` lands last -- leaving the button
+	// showing play over a track that is audibly running.
 	p.emitPlaybackFinished()
 
 	events.Emit(
@@ -513,6 +576,8 @@ func (p *Player) onPlaybackFinished() {
 		map[string]string{"state": string(Stopped)},
 	)
 
+	p.mu.Unlock()
+
 	// Notify media controls outside the lock. The track just
 	// ended so position is 0.
 	if mc != nil {
@@ -521,12 +586,19 @@ func (p *Player) onPlaybackFinished() {
 		)
 	}
 
-	p.logger.Info("Playback finished naturally")
+	if srcErr != nil {
+		p.logger.Error(
+			"Playback stopped: the audio source failed",
+			"err", srcErr,
+		)
+	} else {
+		p.logger.Info("Playback finished naturally")
+	}
 
 	// Notify queue for auto-advance. Called without p.mu held
 	// because it re-enters the player via LoadFile/Play.
 	if handler != nil {
-		handler()
+		handler(srcErr)
 	}
 }
 
@@ -587,6 +659,18 @@ func (p *Player) loadFileLocked(filePath string) error {
 
 	p.currentFile = f
 
+	// The decoder's own format, kept for the paths that rebuild the
+	// chain later: Play()'s replay branch resamples from it, so a
+	// stale rate there plays a finished track back at the wrong speed.
+	p.format = format
+
+	// The previous track's duration must not outlive it.  This is set
+	// again by emitTrackChanged below, but only when the database has
+	// a row for the file -- and every position this player reports is
+	// scaled by it, so inheriting means every report is wrong by the
+	// ratio between two unrelated tracks.
+	p.trackLengthMs = 0
+
 	if err := p.updateStreamers(
 		streamer, format.SampleRate,
 	); err != nil {
@@ -906,6 +990,8 @@ func (p *Player) CurrentPosition() (int, error) {
 		return 0, errNoAudioFileLoaded
 	}
 
+	defer p.lockSourceLocked()()
+
 	speaker.Lock()
 	pos := math.Round(
 		100.0 * float64(p.seeker.Position()) /
@@ -924,6 +1010,28 @@ func (p *Player) Seek(targetSeconds int) error {
 	return p.seekLocked(targetSeconds)
 }
 
+// lockSourceLocked blocks the read-ahead goroutine from touching the
+// decoder and returns the function that releases it, so a caller can
+// `defer p.lockSourceLocked()()`.
+//
+// Reading the decoder's position is a read *of the decoder*, and the
+// speaker lock does not exclude the read-ahead goroutine -- it never
+// takes it.  That was a genuine data race on every position emit,
+// once a second for the whole of playback.
+//
+// srcMu is not reentrant, so nothing that already holds it may call
+// this; seekSourceLocked exists to keep that region free of emits.
+// Must be called with p.mu held.
+func (p *Player) lockSourceLocked() func() {
+	if p.buffered == nil {
+		return func() {}
+	}
+
+	p.buffered.LockSource()
+
+	return p.buffered.UnlockSource
+}
+
 // rewindLocked returns the decoder to the start of the track without
 // touching playback state.  Must be called with p.mu held.
 func (p *Player) rewindLocked() {
@@ -959,6 +1067,46 @@ func (p *Player) seekLocked(targetSeconds int) error {
 		return fmt.Errorf("cannot get track length: %w", err)
 	}
 
+	// The source lock is released before anything below is emitted:
+	// emitPositionLocked reads the decoder's position and takes the
+	// same lock, which is not reentrant.
+	seekErr := p.seekSourceLocked(targetSeconds, lengthSecs)
+	if seekErr != nil {
+		p.logger.Warn(
+			"Seek failed, playback will start from "+
+				"the beginning",
+			"target-seconds", targetSeconds,
+			"err", seekErr,
+		)
+
+		// The optimistic move the UI already made has to be taken
+		// back, and only the backend knows it did not happen.
+		events.Emit(p.ctx, events.SeekFailed)
+		p.emitPositionLocked()
+
+		return fmt.Errorf("failed to seek: %w", seekErr)
+	}
+
+	if p.mediaControls != nil {
+		p.mediaControls.NotifySeek(targetSeconds)
+	}
+
+	// Report the landing position immediately rather than leaving the
+	// UI to guess until the next tick — this is the half of H-3 that
+	// desynced the seek bar by 30 s over four keyboard seeks.
+	p.emitPositionLocked()
+
+	return nil
+}
+
+// seekSourceLocked moves the decoder and flushes the stale read-ahead
+// behind it.  It owns the source lock for exactly that long and
+// emits nothing, so its caller is free to read the position
+// afterwards.  Must be called with p.mu held.
+func (p *Player) seekSourceLocked(
+	targetSeconds int,
+	lengthSecs int,
+) error {
 	// Block the read-ahead goroutine from reading the source while
 	// we seek it. The decoder (e.g. FLAC's bufseekio.ReadSeeker) is
 	// not safe for concurrent Read+Seek, and read-ahead runs on its
@@ -1014,19 +1162,11 @@ func (p *Player) seekLocked(targetSeconds int) error {
 	if seekErr != nil {
 		speaker.Unlock()
 
-		p.logger.Warn(
+		p.logger.Debug(
-			"Seek failed, playback will start from "+
+			"seek rejected by the decoder",
-				"the beginning",
+			"samples", samples, "err", seekErr,
-			"target-seconds", targetSeconds,
-			"samples", samples,
-			"err", seekErr,
 		)
 
-		// The optimistic move the UI already made has to be taken
-		// back, and only the backend knows it did not happen.
-		events.Emit(p.ctx, events.SeekFailed)
-		p.emitPositionLocked()
-
 		return fmt.Errorf("failed to seek: %w", seekErr)
 	}
 
@@ -1039,15 +1179,6 @@ func (p *Player) seekLocked(targetSeconds int) error {
 		p.buffered.Flush()
 	}
 
-	if p.mediaControls != nil {
-		p.mediaControls.NotifySeek(targetSeconds)
-	}
-
-	// Report the landing position immediately rather than leaving the
-	// UI to guess until the next tick — this is the half of H-3 that
-	// desynced the seek bar by 30 s over four keyboard seeks.
-	p.emitPositionLocked()
-
 	return nil
 }
 
@@ -1140,6 +1271,10 @@ func (p *Player) seekerLengthSecsLocked() (int, error) {
 		return 0, errNoAudioFileLoaded
 	}
 
+	// Len is fixed for the life of the decoder, so unlike Position it
+	// races with nothing and needs no source lock -- which it must not
+	// take anyway: displayPositionSecsLocked calls this while holding
+	// it, and srcMu is not reentrant.
 	speaker.Lock()
 	length := p.seeker.Len() / int(p.format.SampleRate)
 	speaker.Unlock()
@@ -1156,6 +1291,8 @@ func (p *Player) displayPositionSecsLocked() int {
 		return 0
 	}
 
+	defer p.lockSourceLocked()()
+
 	speaker.Lock()
 	pos := p.seeker.Position()
 	total := p.seeker.Len()

backend/queue/fallback_test.go

@@ -83,7 +83,7 @@ func TestFallback_TriggersOnNaturalFinish(t *testing.T) {
 	q.SetFallbackSource(fake)
 
 	q.SetQueue(seedPaths, 0, false, Source{Type: "album", ID: 1, Label: "Seed Album"})
-	q.OnPlaybackFinished()
+	q.OnPlaybackFinished(nil)
 
 	waitUntil(t, func() bool { return fake.callCount() == 1 }, "fallback to be resolved")
 	waitUntil(t, func() bool {
@@ -159,7 +159,7 @@ func TestFallback_EmptyResultLeavesQueueExhausted(t *testing.T) {
 	q.SetFallbackSource(fake)
 
 	q.SetQueue(seedPaths, 0, false, Source{})
-	q.OnPlaybackFinished()
+	q.OnPlaybackFinished(nil)
 
 	waitUntil(t, func() bool { return fake.callCount() == 1 }, "fallback to be resolved")
 
@@ -193,7 +193,7 @@ func TestFallback_StaleResolutionDiscarded(t *testing.T) {
 	q.SetFallbackSource(fake)
 
 	q.SetQueue(seedPaths, 0, false, Source{})
-	q.OnPlaybackFinished() // starts resolving, blocked on gate
+	q.OnPlaybackFinished(nil) // starts resolving, blocked on gate
 
 	time.Sleep(20 * time.Millisecond) // let the goroutine reach the gate
 

backend/queue/finished_test.go

@@ -0,0 +1,78 @@
+package queue
+
+import (
+	"errors"
+	"testing"
+
+	"yellowjacket/backend/events"
+)
+
+// errTestDecode stands in for a decoder blowing up mid-track.
+var errTestDecode = errors.New("decode blew up")
+
+// currentIndex == -1 against a non-empty queue is a state this
+// package produces on purpose: onQueueExhausted(false) sets it and
+// deliberately leaves the finished track loaded in the player, so it
+// stays on the now-playing bar. Pressing play from there and letting
+// it finish re-enters OnPlaybackFinished with exactly that pair --
+// which used to index q.tracks[-1] and panic, on a goroutine
+// dispatched from the audio callback with no caller to recover it.
+func TestFinishedWithNoCurrentTrackDoesNotPanic(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name  string
+		index int
+	}{
+		{"exhausted queue leaves -1", -1},
+		{"index past the end", 3},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			q, _, _ := setupRecordedQueue(t)
+			q.tracks = []Track{
+				{FilePath: "/a.mp3"},
+				{FilePath: "/b.mp3"},
+			}
+			q.currentIndex = tt.index
+
+			// The assertion is that this returns at all.
+			q.OnPlaybackFinished(nil)
+
+			if q.currentIndex != tt.index {
+				t.Errorf(
+					"an out-of-range index was acted on: %d became %d",
+					tt.index, q.currentIndex,
+				)
+			}
+		})
+	}
+}
+
+// A track that broke mid-playback is not a track that was listened
+// to. The player cannot say so itself -- the metadata is here -- so
+// it hands the reason over and this is where it becomes a
+// PlaybackFailed rather than a silent auto-advance.
+func TestAFailedTrackIsReportedAndNotCountedAsAPlay(t *testing.T) {
+	t.Parallel()
+
+	q, _, rec := setupRecordedQueue(t)
+	q.tracks = []Track{
+		{FilePath: "/a.mp3", Title: "A", AudioFileID: 1},
+		{FilePath: "/b.mp3", Title: "B", AudioFileID: 2},
+	}
+	q.currentIndex = 0
+
+	q.OnPlaybackFinished(errTestDecode)
+
+	if _, ok := rec.Last(events.PlaybackFailed); !ok {
+		t.Errorf(
+			"a track that failed mid-playback told the user nothing; "+
+				"got %v",
+			rec.Names(),
+		)
+	}
+}

backend/queue/handlers.go

@@ -1,18 +1,45 @@
 package queue
 
-// OnPlaybackFinished is called when a track finishes playing naturally.
+// OnPlaybackFinished is called when a track stops streaming. This
-// This drives the auto-advance behavior and records the play.
+// drives the auto-advance behavior and records the play.
-func (q *Queue) OnPlaybackFinished() {
+//
+// srcErr says why the track stopped: nil for one that reached its
+// end, non-nil for one that broke partway through.  The player cannot
+// tell the user which, because the metadata lives here -- so a failure
+// is reported as PlaybackFailed and *not* recorded as a play, while
+// the advance happens either way.  Before this, a file that failed
+// mid-track advanced in silence and was counted as listened to.
+//
+//wails:ignore // internal wiring, not part of the app's IPC surface.
+func (q *Queue) OnPlaybackFinished(srcErr error) {
 	q.mu.Lock()
 
-	if len(q.tracks) == 0 {
+	// currentIndex is -1 whenever the queue has been exhausted, and
+	// onQueueExhausted deliberately leaves the finished track loaded
+	// in the player -- so a natural finish can re-enter here against a
+	// queue that is not empty and an index that is not valid.  Every
+	// other path in this package bounds-checks before indexing; this
+	// one panicked, on a goroutine with no caller to recover it.
+	if q.currentIndex < 0 || q.currentIndex >= len(q.tracks) {
 		q.mu.Unlock()
 
 		return
 	}
 
 	// Capture the track that just finished before advancing.
-	finishedID := q.tracks[q.currentIndex].AudioFileID
+	finished := q.tracks[q.currentIndex]
+	finishedID := finished.AudioFileID
+
+	if srcErr != nil {
+		q.emitPlaybackFailed(finished, srcErr)
+	}
+
+	// A track that broke was not listened to.
+	recordFinished := func() {
+		if srcErr == nil {
+			q.recordPlay(finishedID)
+		}
+	}
 
 	// Repeat One: replay the current track.
 	if q.repeatMode == RepeatOne {
@@ -21,7 +48,7 @@ func (q *Queue) OnPlaybackFinished() {
 		}
 
 		q.mu.Unlock()
-		q.recordPlay(finishedID)
+		recordFinished()
 
 		return
 	}
@@ -31,7 +58,7 @@ func (q *Queue) OnPlaybackFinished() {
 		// Queue exhausted — this is the extension point for a future fallback playlist.
 		q.onQueueExhausted(false)
 		q.mu.Unlock()
-		q.recordPlay(finishedID)
+		recordFinished()
 
 		return
 	}
@@ -44,12 +71,12 @@ func (q *Queue) OnPlaybackFinished() {
 	if !q.playCurrentOrSkip(true, q.nextIndex) {
 		q.onQueueExhausted(false)
 		q.mu.Unlock()
-		q.recordPlay(finishedID)
+		recordFinished()
 
 		return
 	}
 
 	q.emitIndexChanged()
 	q.mu.Unlock()
-	q.recordPlay(finishedID)
+	recordFinished()
 }

backend/queue/playbackfailed_test.go

@@ -107,7 +107,7 @@ func TestPlaybackFailed_AutoAdvanceSkipsPastIt(t *testing.T) {
 
 	// The first track finished: auto-advance lands on the missing
 	// file and must step over it rather than stopping dead.
-	q.OnPlaybackFinished()
+	q.OnPlaybackFinished(nil)
 
 	if got := q.GetState().CurrentIndex; got != 2 {
 		t.Errorf("currentIndex after skipping: got %d, want 2", got)
@@ -183,7 +183,7 @@ func TestQueueExhausted_KeepsTheFinishedTrackLoaded(t *testing.T) {
 
 	q.SetQueue(paths, 0, false, Source{})
 	q.Play()
-	q.OnPlaybackFinished()
+	q.OnPlaybackFinished(nil)
 
 	if q.GetState().CurrentIndex != -1 {
 		t.Errorf(

e2e/specs/album-dropdown.spec.ts

@@ -1,6 +1,12 @@
 import { test, expect } from '../support/fixtures.js';
 import type { Page } from '@playwright/test';
 
+/**
+ * How far the scroll test scrolls. One constant, because the guard and
+ * the assertion have to agree about it — they did not, which is #133.
+ */
+const SCROLL_TARGET = 80;
+
 /**
  * Plan 007 phase 5: expanding an album shows its tracks.
  *
@@ -104,20 +110,27 @@ test.describe('the album dropdown', () => {
     await app.setViewportSize({ width: 900, height: 600 });
 
     try {
-      await expect.poll(() => scrollRange(app)).toMatchObject({
+      // Wait for the range the assertion below actually needs, not for
-        scrollable: true,
+      // "scrollable at all" (#133). The guard used to be
-        overflowY: 'auto',
+      // `scrollHeight > clientHeight + 40` while the next line asks to
-      });
+      // reach 80, so any range in 41-79 satisfied it and could not
+      // satisfy the assertion — and the grid passes through exactly
+      // that while it settles, because it recomputes its columns after
+      // the resize rather than during it. The settled range here is
+      // 330, so this waits rather than weakening anything.
+      await expect
+        .poll(() => scrollRange(app))
+        .toMatchObject({ room: true, overflowY: 'auto' });
 
-      await app.evaluate(() => {
+      await app.evaluate((target) => {
         const sc = document
           .querySelector('cover-grid')
           ?.shadowRoot?.querySelector('.grid-scroll-container');
 
-        if (sc) sc.scrollTop = 80;
+        if (sc) sc.scrollTop = target;
-      });
+      }, SCROLL_TARGET);
 
-      expect(await scrollTop(app)).toBe(80);
+      expect(await scrollTop(app)).toBe(SCROLL_TARGET);
 
       // And the dropdown it opens is on screen, wherever the manager
       // decides that leaves the scroll. It is *not* "the position is
@@ -250,16 +263,19 @@ async function closeDropdown(app: Page): Promise<void> {
 
 /** Whether the grid can scroll at all, which decides if a probe can move. */
 async function scrollRange(app: Page) {
-  return app.evaluate(() => {
+  return app.evaluate((target) => {
     const sc = document
       .querySelector('cover-grid')
       ?.shadowRoot?.querySelector('.grid-scroll-container');
 
     return {
-      scrollable: !!sc && sc.scrollHeight > sc.clientHeight + 40,
+      // `room` is the precondition of the assertion that follows it:
+      // enough range to actually reach the target. A threshold below
+      // what the caller depends on is not a guard.
+      room: !!sc && sc.scrollHeight - sc.clientHeight >= target,
       overflowY: sc ? getComputedStyle(sc).overflowY : '',
     };
-  });
+  }, SCROLL_TARGET);
 }
 
 async function scrollTop(app: Page): Promise<number> {

frontend/bindings/yellowjacket/backend/queue/queue.ts

@@ -113,14 +113,6 @@ export function Next(): $CancellablePromise<void> {
     return $Call.ByID(1968784044);
 }
 
-/**
- * OnPlaybackFinished is called when a track finishes playing naturally.
- * This drives the auto-advance behavior and records the play.
- */
-export function OnPlaybackFinished(): $CancellablePromise<void> {
-    return $Call.ByID(2184869763);
-}
-
 /**
  * Play handles a play request by either resuming the current track or
  * starting playback from the beginning of the queue. When a track is

frontend/src/components/home-view/home-view.ts

@@ -160,29 +160,52 @@ export class HomeView extends ViewLifecycleMixin(LitElement) {
                 user-select: none;
             }
 
+            /*
+             * The hover play button is a *hover* affordance, so it is
+             * gated on the device having hover rather than on width.  A
+             * touch long-press synthesises a hover state in the WebView,
+             * so on a phone it flashed into view during the 500ms hold
+             * that utils/long-press.ts is measuring for a context menu —
+             * a control appearing because you were reaching for a
+             * different one.  A phone user taps the album and plays from
+             * the detail view, so there is nothing to replace it with.
+             *
+             * display:none outside the query rather than opacity:0 on
+             * its own: an opacity-0 button still takes taps and is
+             * still in the accessibility tree, so the invisible control
+             * would keep the hit area it was never meant to have on
+             * touch. Everything else stays inside, so the desktop
+             * animation is unchanged.
+             */
             .play {
-                position: absolute;
+                display: none;
-                right: 8px;
-                bottom: 8px;
-                width: 38px;
-                height: 38px;
-                border: none;
-                border-radius: 50%;
-                background: var(--yj-accent, #ffd43b);
-                color: var(--yj-accent-fg, #000);
-                display: flex;
-                align-items: center;
-                justify-content: center;
-                cursor: pointer;
-                opacity: 0;
-                transform: translateY(6px);
-                transition: opacity 0.12s ease, transform 0.12s ease;
             }
 
-            .card:hover .play,
+            @media (hover: hover) and (pointer: fine) {
-            .card:focus-within .play {
+                .play {
-                opacity: 1;
+                    position: absolute;
-                transform: translateY(0);
+                    right: 8px;
+                    bottom: 8px;
+                    width: 38px;
+                    height: 38px;
+                    border: none;
+                    border-radius: 50%;
+                    background: var(--yj-accent, #ffd43b);
+                    color: var(--yj-accent-fg, #000);
+                    display: flex;
+                    align-items: center;
+                    justify-content: center;
+                    cursor: pointer;
+                    opacity: 0;
+                    transform: translateY(6px);
+                    transition: opacity 0.12s ease, transform 0.12s ease;
+                }
+
+                .card:hover .play,
+                .card:focus-within .play {
+                    opacity: 1;
+                    transform: translateY(0);
+                }
             }
 
             .name {

frontend/src/components/now-playing/now-playing.ts

@@ -13,6 +13,7 @@ import {
     isQueueSourceNavigable,
     navigateToQueueSource,
 } from '@utils/queue-source-link';
+import { PHONE_QUERY } from '@utils/breakpoints';
 import { PlayerController } from '@store/controllers/player-controller';
 import { creditStore } from '@store/credit-store';
 import { QueueController } from '@store/controllers/queue-controller';
@@ -80,6 +81,19 @@ export class NowPlaying extends LitElement {
 
     private reduceMotionQuery?: MediaQueryList;
 
+    /**
+     * Phone width, from the shell's own breakpoint.
+     *
+     * This is in JS rather than in the stylesheet because what changes
+     * is the *content*, not its appearance: the title, artist and
+     * source render as plain text instead of as links, and no CSS rule
+     * can take a click handler off an element.
+     */
+    @state()
+    private phone = false;
+
+    private phoneQuery?: MediaQueryList;
+
     /** Whether each field is actively mid-scroll (class toggle). */
     @state()
     private titleScrolling = false;
@@ -341,6 +355,12 @@ export class NowPlaying extends LitElement {
         this.reduceMotion = this.reduceMotionQuery?.matches ?? false;
         this.reduceMotionQuery?.addEventListener('change', this.handleReduceMotionChange);
 
+        // Same reasoning as above: looked up here, not at module load,
+        // so a test can install its own matchMedia first.
+        this.phoneQuery = window.matchMedia?.(PHONE_QUERY);
+        this.phone = this.phoneQuery?.matches ?? false;
+        this.phoneQuery?.addEventListener('change', this.handlePhoneChange);
+
         this.resizeObserver = new ResizeObserver(() => {
             this.geometryDirty = true;
             this.requestUpdate();
@@ -364,6 +384,7 @@ export class NowPlaying extends LitElement {
         this.attachDragListeners(false);
         window.removeEventListener(SCROLL_CHANGE_EVENT, this.handleScrollModeEvent);
         this.reduceMotionQuery?.removeEventListener('change', this.handleReduceMotionChange);
+        this.phoneQuery?.removeEventListener('change', this.handlePhoneChange);
         this.resizeObserver?.disconnect();
         this.stopScrollCycle('title');
         this.stopScrollCycle('artist');
@@ -488,7 +509,7 @@ export class NowPlaying extends LitElement {
               @mouseleave=${this.handleTitleMouseLeave}
               @transitionend=${() => this.onScrollCycleEnd('title')}
             >
-              <span class="scroll-content">${trackLink(track.title, track.album, track.releaseGroupMbid, track.recordingMbid) || track.title}</span>
+              <span class="scroll-content">${this.phone ? track.title : trackLink(track.title, track.album, track.releaseGroupMbid, track.recordingMbid) || track.title}</span>
             </span>
             <span
               class="track-artist ${artistScrolling ? 'will-scroll' : ''} ${this.artistScrolling ? 'scrolling' : ''}"
@@ -498,14 +519,15 @@ export class NowPlaying extends LitElement {
               @mouseleave=${this.handleArtistMouseLeave}
               @transitionend=${() => this.onScrollCycleEnd('artist')}
             >
-              <span class="scroll-content">${creditLink(creditStore.credits(track.recordingMbid), track.artist, track.artistMbid) || 'Unknown Artist'}</span>
+              <span class="scroll-content">${this.phone ? track.artist || 'Unknown Artist' : creditLink(creditStore.credits(track.recordingMbid), track.artist, track.artistMbid) || 'Unknown Artist'}</span>
             </span>
             ${describeQueueSource(this.queue.source)
                 ? html`
                   <span
-                    class="track-source ${isQueueSourceNavigable(this.queue.source) ? 'navigable' : ''}"
+                    class="track-source ${!this.phone && isQueueSourceNavigable(this.queue.source) ? 'navigable' : ''}"
                     data-testid="now-playing-source"
                     @click=${(e: MouseEvent) => {
+                        if (this.phone) return;
                         if (!isQueueSourceNavigable(this.queue.source)) return;
                         navigateToQueueSource(
                             e.currentTarget as EventTarget,
@@ -571,6 +593,10 @@ export class NowPlaying extends LitElement {
         this.reduceMotion = e.matches;
     };
 
+    private handlePhoneChange = (e: MediaQueryListEvent): void => {
+        this.phone = e.matches;
+    };
+
     private shouldScroll(field: 'title' | 'artist'): boolean {
         const overflows = field === 'title' ? this.titleOverflows : this.artistOverflows;
 
@@ -606,6 +632,12 @@ export class NowPlaying extends LitElement {
             track?.artist ?? '',
             this.shouldScroll('title') ? '1' : '0',
             this.shouldScroll('artist') ? '1' : '0',
+            // Crossing the breakpoint swaps a link for a bare string,
+            // and a link is not guaranteed to measure the same as the
+            // text inside it. The marquee travels a distance read from
+            // that measurement, so this belongs in the key even though
+            // the words are identical either side.
+            this.phone ? '1' : '0',
         ].join('\u0000');
     }
 

frontend/src/components/track-list/track-list.ts

@@ -11,6 +11,7 @@ import {
 import { SelectionController } from '@utils/selection-controller';
 import type { SelectionHost } from '@utils/selection-controller';
 import { ViewLifecycleMixin } from '@utils/view-lifecycle';
+import { PHONE_QUERY } from '@utils/breakpoints';
 import {
     ContextMenuController,
     contextMenuStyles,
@@ -105,9 +106,6 @@ const ROW_CHROME_WIDTH =
 const ROW_HEIGHT = 33;
 const PHONE_ROW_HEIGHT = 52;
 
-/** The shell's phone breakpoint, as `index.css` and every component
- *  stylesheet spells it. */
-const PHONE_QUERY = '(max-width: 599px)';
 
 // Inline SVG paths for favorite icons — eliminates wa-icon shadow DOM
 // overhead (30-50 shadow roots during scroll).  Font Awesome 6 paths.

frontend/src/utils/breakpoints.ts

@@ -0,0 +1,23 @@
+/**
+ * The shell's breakpoints, where JavaScript has to agree with CSS.
+ *
+ * A media query inside a shadow root is answered by the viewport, so a
+ * component normally states what it drops at phone width in its own
+ * stylesheet and needs nothing from here. This exists for the cases
+ * where the decision is not a style: `track-list` computes its grid in
+ * JS from the host width, and `now-playing` renders *different content*
+ * on a phone — a plain string instead of a link — which no stylesheet
+ * can express.
+ *
+ * One breakpoint, several expressions of it. It was a private const in
+ * track-list.ts when there was one; a second reader is where a copy
+ * would start drifting from index.css.
+ */
+
+/**
+ * Phone width. 600px rather than the sidebar's 900px because 900 is a
+ * laptop: the answer there is a narrower sidebar, which is still a
+ * sidebar. Below this the shell drops the sidebar column entirely and
+ * bottom-nav takes over.
+ */
+export const PHONE_QUERY = '(max-width: 599px)';

frontend/test/components/hover-affordance.test.ts

@@ -0,0 +1,85 @@
+/**
+ * A hover affordance is gated on the device having hover.
+ *
+ * The home page's cover cards reveal a play button on :hover. A touch
+ * long-press synthesises a hover state in the WebView, so on a phone
+ * that button flashed into view during the 500ms hold that
+ * utils/long-press.ts is measuring for a context menu — a control
+ * appearing because the user was reaching for a different one.
+ *
+ * This is asserted against the *parsed stylesheet* rather than by
+ * emulating a touch device, and that is a limitation worth stating
+ * rather than hiding. CDP's Emulation.setEmulatedMedia does not reach
+ * this tier's iframe — matchMedia still answers `hover: hover` after it
+ * is set — so there is no way here to render the component as a phone
+ * would and read the computed style. What can be checked is the shape
+ * the browser actually built from the css`` literal: that the reveal
+ * lives inside a hover media query and that the default is display:none.
+ *
+ * Which is the regression worth catching anyway. The failure mode is
+ * someone hoisting the rule back out of the query for a one-line tidy —
+ * a change nothing renders differently on a desktop, so every other
+ * assertion in this repo passes and the phone silently regresses.
+ */
+import { describe, expect, it } from 'vitest';
+
+import '@components/home-view/home-view';
+import { fixture } from '@test/support/render';
+
+/** Every rule in the element's own adopted stylesheets, flattened. */
+function rulesOf(host: Element): { text: string; condition: string | null }[] {
+  const sheets = host.shadowRoot?.adoptedStyleSheets ?? [];
+  const out: { text: string; condition: string | null }[] = [];
+
+  for (const sheet of sheets) {
+    for (const rule of Array.from(sheet.cssRules)) {
+      if (rule instanceof CSSMediaRule) {
+        for (const inner of Array.from(rule.cssRules)) {
+          out.push({ text: inner.cssText, condition: rule.conditionText });
+        }
+
+        continue;
+      }
+
+      out.push({ text: rule.cssText, condition: null });
+    }
+  }
+
+  return out;
+}
+
+describe('the home card play button', () => {
+  it('reveals itself only where the device has hover', async () => {
+    const el = await fixture('home-view', {});
+    const rules = rulesOf(el);
+
+    // The sweep is worth nothing if it read no rules at all — the same
+    // first assertion icon-language.test.ts makes for the same reason.
+    expect(rules.length).toBeGreaterThan(0);
+
+    const reveals = rules.filter(
+      (r) => r.text.includes('.play') && /opacity:\s*1/.test(r.text),
+    );
+
+    expect(reveals.length).toBeGreaterThan(0);
+
+    for (const rule of reveals) {
+      expect(rule.condition).toMatch(/hover:\s*hover/);
+      expect(rule.condition).toMatch(/pointer:\s*fine/);
+    }
+  });
+
+  it('is display:none rather than transparent where it is absent', async () => {
+    const el = await fixture('home-view', {});
+
+    // opacity:0 alone would leave a button that still takes taps and is
+    // still in the accessibility tree, so a phone would keep the hit
+    // area for a control it can never see.
+    const unconditional = rulesOf(el).filter(
+      (r) => r.condition === null && r.text.startsWith('.play'),
+    );
+
+    expect(unconditional.length).toBeGreaterThan(0);
+    expect(unconditional.some((r) => /display:\s*none/.test(r.text))).toBe(true);
+  });
+});

frontend/test/components/now-playing-phone.test.ts

@@ -0,0 +1,166 @@
+/**
+ * The mini player's links are a desktop affordance.
+ *
+ * `utils/explore-link.ts` makes every track and artist name navigate,
+ * and `utils/queue-source-link.ts` makes "Playing from X" navigate — in
+ * the bottom bar those are a few characters of text at a font size
+ * chosen for a bar, which is not a touch target. Worse, explore-link
+ * holds the navigation for one double-click interval and drops it if a
+ * second click arrives: a gesture that exists so double-clicking a row
+ * can play it, and which means nothing at all on touch.
+ *
+ * So below the shell's phone breakpoint the three render as plain text
+ * and the whole bar's cover art opens the full-screen Now Playing view,
+ * which is where the links live.
+ *
+ * The breakpoint is stubbed rather than emulated for the reason
+ * track-list-phone.test.ts states: this tier's viewport is fixed at
+ * 1280x800 by the runner, and the component reads matchMedia in
+ * connectedCallback precisely so a test can answer it first.
+ */
+import { describe, expect, it, beforeEach } from 'vitest';
+
+import '@components/now-playing/now-playing';
+import { Events } from '../../src/events';
+import { emit, flush } from '@test/support/harness';
+import { fixture, shadow, shadowAll, text } from '@test/support/render';
+import type { TrackInfo } from '@store/player-store';
+import type { QueueTrack } from '@store/queue-store';
+
+const TRACK: TrackInfo = {
+  fileName: 'ashes.mp3',
+  filePath: '/music/ashes.mp3',
+  trackLength: 215,
+  seekPosition: 0,
+  state: 'playing',
+  title: 'Ashes to Ashes',
+  artist: 'David Bowie',
+  album: 'Scary Monsters',
+  coverArt: '',
+  coverArtSmall: '',
+  coverArtMedium: '',
+  coverArtLarge: '',
+  trackChangeId: 1,
+  artistMbid: '',
+  releaseGroupMbid: '',
+  recordingMbid: '',
+};
+
+function queueTrack(n: number, title: string): QueueTrack {
+  return {
+    id: n,
+    audioFileId: n,
+    filePath: `/music/${n}.mp3`,
+    position: n,
+    title,
+    artist: 'David Bowie',
+    album: 'Scary Monsters',
+    coverArtPath: '',
+    artistMbid: '',
+    releaseGroupMbid: '',
+    recordingMbid: '',
+  };
+}
+
+/** Mount the bar with the phone breakpoint answering `matches`. */
+async function mountAt(phone: boolean) {
+  const real = window.matchMedia.bind(window);
+
+  window.matchMedia = ((q: string) =>
+    q.includes('max-width: 599px')
+      ? {
+          matches: phone,
+          media: q,
+          addEventListener() {},
+          removeEventListener() {},
+        }
+      : real(q)) as typeof window.matchMedia;
+
+  try {
+    const el = await fixture('now-playing');
+
+    emit(Events.TrackChanged, { ...TRACK, trackChangeId: 20 });
+    emit(Events.QueueChanged, {
+      tracks: [queueTrack(1, 'Ashes to Ashes')],
+      currentIndex: 0,
+      source: { type: 'album', id: 7, label: 'Scary Monsters' },
+    });
+    await flush();
+    await el.updateComplete;
+
+    return el;
+  } finally {
+    window.matchMedia = real;
+  }
+}
+
+describe('the mini player on a phone', () => {
+  beforeEach(() => {
+    emit(Events.TrackChanged, { ...TRACK, trackChangeId: 1 });
+  });
+
+  it('renders the title and artist as plain text', async () => {
+    const el = await mountAt(true);
+
+    expect(shadowAll(el, '.explore-link').length).toBe(0);
+
+    // The words are unchanged — this is about what they are, not about
+    // hiding them. A fix that dropped the text would pass an assertion
+    // about links alone.
+    expect(text(el, '[data-testid="now-playing-title"]')).toContain(
+      'Ashes to Ashes',
+    );
+    expect(text(el, '[data-testid="now-playing-artist"]')).toContain(
+      'David Bowie',
+    );
+  });
+
+  it('does not navigate from the source line', async () => {
+    const el = await mountAt(true);
+    const source = shadow<HTMLElement>(el, '[data-testid="now-playing-source"]');
+
+    expect(source?.classList.contains('navigable')).toBe(false);
+
+    let navigated = false;
+    el.addEventListener('navigate', () => {
+      navigated = true;
+    });
+
+    source?.click();
+
+    expect(navigated).toBe(false);
+  });
+
+  it('still says where the queue came from', async () => {
+    const el = await mountAt(true);
+
+    // Dropping the *link* is the change; dropping the information would
+    // be a different and worse one.
+    expect(text(el, '[data-testid="now-playing-source"]')).toBe(
+      'Playing from Scary Monsters',
+    );
+  });
+
+  it('leaves the desktop bar exactly as it was', async () => {
+    const el = await mountAt(false);
+
+    expect(shadowAll(el, '.explore-link').length).toBeGreaterThan(0);
+
+    const source = shadow<HTMLElement>(el, '[data-testid="now-playing-source"]');
+
+    expect(source?.classList.contains('navigable')).toBe(true);
+
+    let detail: unknown;
+    el.addEventListener('navigate', (e) => {
+      detail = (e as CustomEvent).detail;
+    });
+
+    source?.click();
+
+    expect(detail).toEqual({
+      view: 'explore-album-details',
+      localAlbumId: 7,
+      albumName: 'Scary Monsters',
+    });
+  });
+});

lefthook.yml

@@ -20,19 +20,14 @@ pre-commit:
       glob: "*.go"
       run: go tool golangci-lint run --timeout 5m ./...
 
+    # Snapshots the tree either side of the generators and reports only
+    # what moved across them.  This used to be `go generate` plus a bare
+    # `git diff --name-only`, which is the *whole unstaged worktree* — so
+    # any unrelated edit sitting there was reported as stale generated
+    # code, and `make generate` then fixed nothing.  See the script.
     codegen-check:
       glob: "*.{go,sql,templ}"
-      run: |
+      run: ./scripts/codegen-check.sh
-        go generate ./...
-        if [ -n "$(git diff --name-only)" ]; then
-          echo "Generated code is out of date. Run 'make generate' and stage the changes."
-          # --no-pager, or this blocks forever on `less` waiting for a
-          # keypress that a hook run without a tty will never get: the
-          # commit hangs at exactly the moment it is trying to tell you
-          # why it failed.
-          git --no-pager diff --stat
-          exit 1
-        fi
 
     # frontend/bindings is generated by `wails3`, not `go generate`, so
     # the check above does not cover it.  ~3.5s warm, ~20s on a cold
@@ -63,8 +58,17 @@ pre-commit:
       root: "frontend/"
       run: node scripts/check-css-literals.mjs
 
+# Deliberately sequential, unlike pre-commit.  `go test -race`
+# saturates every core for the better part of a minute and the UI tier
+# is a real browser with wall-clock timeouts, so run together the
+# browser loses: setup took 106s inside the hook against 63s
+# standalone, and a different suite failed each time -- three suites
+# failing to fetch setup.ts from Vitest's own dev server on one run, a
+# 15s "did not mount itself" on the next, against a suite that passes
+# 898/898 on its own. A gate that fails at random is not a gate. The
+# ~15s saved is not worth it.
 pre-push:
-  parallel: true
+  parallel: false
   commands:
     go-test:
       glob: "*.go"

scripts/codegen-check.sh

@@ -0,0 +1,81 @@
+#!/usr/bin/env bash
+#
+# Fails when `go generate ./...` would change something that is not staged.
+#
+# The obvious spelling of this is `go generate && git diff --name-only`,
+# which is what the hook used to be, and it answers the wrong question:
+# that diff is the *whole unstaged worktree*, so any unrelated edit — a
+# note, a plan document, the next commit's files sitting there while this
+# one lands — was reported as
+#
+#     Generated code is out of date. Run 'make generate' and stage the changes.
+#
+# Running `make generate` then does nothing, because nothing generated is
+# stale, and the message sends you looking for a codegen problem that does
+# not exist.  Splitting one piece of work into several commits is exactly
+# the shape that triggers it, so the workaround was a constraint on commit
+# order for no real reason.
+#
+# So the tree is snapshotted either side of the generators and only what
+# *moved across them* is reported.  That is deliberately not a list of
+# generated paths: sqlcgen, `*_templ.go` and `frontend/src/events.ts` are
+# today's answer, a fourth generator is one `//go:generate` line away, and
+# a path list is a second place to remember it — the same reasoning that
+# keeps staleshape.go parsing sql/schemas/ rather than restating it.
+#
+# Content, not names: a generated file that is *already* dirty and is then
+# rewritten further keeps its name in both snapshots and would otherwise
+# slip through.
+
+set -euo pipefail
+
+cd "$(dirname "$0")/.."
+
+# name + worktree blob hash for every file that differs from the index.
+# A file listed but absent (a deletion) hashes as "gone" rather than
+# aborting the pipeline.
+snapshot() {
+	git diff --name-only | while IFS= read -r f; do
+		if [ -f "$f" ]; then
+			printf '%s %s\n' "$f" "$(git hash-object -- "$f")"
+		else
+			printf '%s gone\n' "$f"
+		fi
+	done
+}
+
+# A brand-new generated file is not in either diff, because it is not
+# tracked at all — the same blind spot bindings-check.sh names.  Both
+# snapshots are taken before the generators run.
+before="$(snapshot)"
+before_untracked="$(git ls-files --others --exclude-standard)"
+
+go generate ./...
+
+after="$(snapshot)"
+after_untracked="$(git ls-files --others --exclude-standard)"
+
+# Symmetric difference, and the symmetry is the whole point.  Generation
+# can push a file *into* the unstaged set (it was current, now it is not)
+# or *out* of it (someone hand-edited generated output and the generator
+# put it back) — and the second is stale generated code just as much as
+# the first.  Comparing one direction only reports "current" for it,
+# which is the failure this script was written to stop.
+moved="$(comm -3 <(printf '%s\n' "$before" | sort) <(printf '%s\n' "$after" | sort) |
+	cut -d' ' -f1 | tr -d '\t' | sort -u | grep -v '^$' || true)"
+
+if [ -n "$moved" ]; then
+	echo "codegen-check: generated code is out of date." >&2
+	echo "Run 'make generate' and stage:" >&2
+	printf '  %s\n' $moved >&2
+	exit 1
+fi
+
+if [ "$after_untracked" != "$before_untracked" ]; then
+	echo "codegen-check: generation produced new files. Stage them:" >&2
+	comm -13 <(printf '%s\n' "$before_untracked" | sort) \
+		<(printf '%s\n' "$after_untracked" | sort) >&2
+	exit 1
+fi
+
+echo "codegen-check: generated code is current"

scripts/dev-headless.sh

@@ -97,6 +97,55 @@ if [ -f "$PID_FILE" ] && kill -0 "$(cat "$PID_FILE")" 2>/dev/null; then
 fi
 rm -f "$PID_FILE"
 
+# ── Refuse to inherit somebody else's port ───────────────────────────
+# The PID check above only knows about *this* worktree: `make dev-stop`
+# kills the pid in this .dev/app.pid and nothing else.  Several worktrees
+# of this repo share the default port, so an app orphaned by a deleted
+# worktree goes on listening with nothing left to stop it.
+#
+# Without this check the new app starts, fails to bind, exits — and every
+# curl and playwright-cli call afterwards goes to the *other* process, so
+# the harness reports facts about an app nobody asked for.  That is not a
+# quiet wrongness either: it presented as
+# "no such table: libraries" against a freshly created YJ_HOME, which
+# reads exactly like applySchema or staleshape.go having gone wrong and
+# is a frightening place to start looking.
+#
+# The startup wait below cannot catch it, because the health check is
+# satisfied by *any* app on the port — which is precisely the failure.
+# So it is refused here, before anything is launched, rather than warned
+# about.  --port already exists for the legitimate second-app case.
+port_holder() {
+	command -v ss >/dev/null || return 0
+	ss -lptn "sport = :$PORT" 2>/dev/null | grep -oP 'pid=\K[0-9]+' | head -n 1
+}
+
+if curl -sf -o /dev/null --max-time 2 "http://localhost:$PORT/" ||
+	[ -n "$(port_holder)" ]; then
+	holder="$(port_holder)"
+	echo "dev-headless: :$PORT is already in use; refusing to start" >&2
+	if [ -n "$holder" ]; then
+		# /proc/<pid>/cwd names the checkout it belongs to, and says
+		# "(deleted)" for the orphaned-worktree case that is the whole
+		# reason this is worth a check.
+		cwd="$(readlink "/proc/$holder/cwd" 2>/dev/null || echo unknown)"
+		cmd="$(tr '\0' ' ' <"/proc/$holder/cmdline" 2>/dev/null || echo unknown)"
+		echo "  pid  $holder  ($cmd)" >&2
+		echo "  cwd  $cwd" >&2
+		# The PID-file check above has already passed, so whatever this
+		# is, `make dev-stop` does not know about it — saying otherwise
+		# sends you to a command that will report success and change
+		# nothing.  Never `pkill -f` here either: the pattern would
+		# match this script's own command line.
+		echo "  'make dev-stop' will not touch it (it is not in" >&2
+		echo "  ${PID_FILE#"$REPO_ROOT"/}): kill $holder, or pass --port." >&2
+	else
+		echo "  The holder could not be identified (no ss, or it belongs" >&2
+		echo "  to another user). Try: ss -lptn 'sport = :$PORT'" >&2
+	fi
+	exit 1
+fi
+
 # ── Choose the YJ_HOME ───────────────────────────────────────────────
 # A seed is a YJ_HOME that a previous run of the app produced, tarred
 # up (see scripts/seed-sandbox.sh).  Restoring it means starting *in*
@@ -200,6 +249,20 @@ until curl -sf -o /dev/null "http://localhost:$PORT/"; do
 	sleep 0.25
 done
 
+# The loop above exits on the first answer from the port, and "something
+# answered" is not "the app we started answered".  The pre-launch guard
+# makes that unlikely rather than impossible — a race, or a listener
+# started in between — and the check is one signal, so it is worth making
+# here too.  An empty log beside a dead pid is the "it exited immediately
+# and nothing said so" case that the original report spent its time on.
+if ! kill -0 "$APP_PID" 2>/dev/null; then
+	echo "dev-headless: :$PORT answered, but the app we started (pid" >&2
+	echo "  $APP_PID) is gone — something else holds the port." >&2
+	tail -n 30 "$LOG_FILE" >&2
+	rm -f "$PID_FILE"
+	exit 1
+fi
+
 cat <<EOF
 dev-headless: up
   url      http://localhost:$PORT

scripts/issue.sh

@@ -38,8 +38,10 @@
 # Where a body is taken and no --body-file is given, it is read from stdin.
 #
 # Environment:
-#   GITEA_TOKEN   a PAT with write:issue (plus write:repository and read:user,
+#   GITEA_TOKEN   a PAT with write:issue.  `claim` and `mine` additionally
-#                 which the rest of this repo's tooling reaches for)
+#                 need to know your username: set GITEA_USER, or give the
+#                 token read:user and it is looked up.
+#   GITEA_USER    your Gitea login.  Optional; see above.
 #   GITEA_URL     defaults to https://git.ljones.me
 #   GITEA_REPO    defaults to yonlu/yellowjacket
 set -euo pipefail
@@ -81,7 +83,29 @@ read_body() {
 	if [ "$file" = "-" ]; then cat; else cat "$file"; fi
 }
 
-me() { curl -sS -H "Authorization: token $GITEA_TOKEN" "$server/api/v1/user" | python3 "$py" login; }
+# The one lookup in this script that needs a scope beyond write:issue.
+# `GET /user` requires read:user, and it is reached for exactly two reasons:
+# to name the assignee in `claim`, and to filter in `mine`.  A token scoped to
+# the work this script does — write:issue — therefore failed at `claim`, which
+# is the one step the workflow requires before the first edit, so the whole
+# documented process was blocked by its own tooling.
+#
+# GITEA_USER short-circuits it, which is what lets a least-privilege token do
+# the job.  The lookup stays as the fallback because it is right when the
+# scope is there and needs no setup at all.
+me() {
+	if [ -n "${GITEA_USER:-}" ]; then
+		printf '%s' "$GITEA_USER"
+		return
+	fi
+	curl -sS -H "Authorization: token $GITEA_TOKEN" "$server/api/v1/user" |
+		python3 "$py" login ||
+		{
+			echo "issue.sh: could not resolve your username. Set GITEA_USER, or" >&2
+			echo "issue.sh: re-issue GITEA_TOKEN with read:user." >&2
+			exit 1
+		}
+}
 
 label_id() { call GET "/labels?limit=100" | python3 "$py" label-id "$1"; }