docs(skill): the WAV fixtures scan tagged, and have since #104

`fixtures.md` told an agent the WAV fixtures scan in untitled, that
there is no "Field Recordings" artist in the Artists view, and that
this is a known open bug "pinned by TestWAVTagsAreNotReadableYet" — a
test #104 deleted, because it existed to assert the reader did not work
and failed the moment it did.

That last clause is why this is worth a diff rather than being left to
rot: the paragraph is an instruction, and it instructs the next reader
that a spec asserting the *working* behaviour is the mistake. It is the
same #104 staleness #217 removed from `queue-selection.spec.ts`, one
file over, still telling agents to put it back.

Measured against a running app rather than corrected from the issue
text — and the seed had to be rebuilt first, since the one on disk
predated #104 and would have replayed a pre-#104 scan and confirmed the
stale paragraph. On a fresh `make sandbox-seed NAME=default`, both WAVs
carry a title, an artist credit and an album: "Field Recordings" is an
ordinary artist with 2 tracks and "Test Tones" has a cover row. The
only two tracks with no album at all are `unsorted/no-tags-at-all.mp3`
and `unsorted/title-only.mp3`.

The replacement also says that prose written before #104 disagrees,
because it does, and saying nothing is how the next reader reintroduces
the claim from a source this change deliberately does not touch.

Deliberately carries no `Closes` footer. #225 covers two halves, and
the second — the same staleness in two *dated* `.planning/NOTES.md`
entries — is left alone: whether measured history gets a correcting
clause is a judgement about what that file is for, which the issue
raises on purpose and this change must not settle by auto-closing it.

.pi/skills/yellowjacket-dev/references/fixtures.md

@@ -42,11 +42,16 @@ strings and identical specs produce different bytes on different builds.
   playback and then clicks pause races the track ending and fails
   against a correct UI. Use `LONG_TRACK` (90 s, `edge-lengths`) exported
   from `e2e/support/fixtures.ts`.
-- **WAV tracks scan in untitled.** `backend/tagwriter` writes WAV tags
-  into a RIFF `id3 ` chunk and `dhowden/tag` has no RIFF parser, so
-  there is no "Field Recordings" artist in the Artists view. This is a
-  known open bug pinned by `TestWAVTagsAreNotReadableYet`; do not
-  "fix" a spec by asserting the broken behaviour elsewhere.
+- **WAV tracks scan like every other format.** #104 added
+  `backend/riff`, so the scan reads the `id3 ` chunk `backend/tagwriter`
+  writes and both WAVs come in fully tagged: "Field Recordings" is an
+  ordinary artist in the Artists view, with a "Test Tones" album and a
+  cover. They are therefore not an example of an untitled or albumless
+  track — the only two tracks with no album are
+  `unsorted/no-tags-at-all.mp3` and `unsorted/title-only.mp3`. Prose
+  written before #104 says the opposite and names
+  `TestWAVTagsAreNotReadableYet`, a test that change deleted; that is
+  dated history rather than a description of the app.
 
 ## Seeds
 

CLAUDE.md

@@ -662,28 +662,6 @@ rather than renaming them.
   one of the shell's rows, which is what the skip link is absolutely
   positioned to avoid.
 - `config` — TOML-based settings. Settings page uses HTMX + templ for server-rendered HTML fragments.
-
-  **A setter that can reject its argument puts the old value back**, and
-  that is a correctness rule rather than hygiene (#231). `Save()`
-  validates the *whole* config, so a value left behind by a failed write
-  does not merely fail its own call: it fails every later save, of every
-  unrelated setting — theme, launch page, shortcuts, libraries — for the
-  rest of the session. Nothing reaches disk, so a restart clears it,
-  which is exactly what makes the fault invisible and unreportable. One
-  rejected track-list column list was enough to stop the app saving
-  anything at all.
-
-  Two shapes are safe and a third is the trap. A setter that assigns and
-  *then* validates snapshots the field first and restores it on the
-  error path — seven do. `SetLibraryDirectory` is the better shape where
-  the value can be built on its own: it validates a candidate *before*
-  assigning, so there is nothing to undo. And a setter whose argument no
-  validation inspects needs neither — the bools, the favourites playlist
-  id and the shortcut bindings, plus `SetViewVisible`, which refuses an
-  unknown, non-hideable or launch-page view up front so
-  `GeneralConfig.Validate` never sees one it would fail on. Which set a
-  new setter joins is decided by whether its own `Validate` can reject
-  it, not by preference.
 - `playlist` / `smartplaylist` — Playlist CRUD and rule-based smart playlists.
 - `mediacontrols` — OS media controls behind one `Handler`: MPRIS over
   D-Bus on desktop Linux, a MediaSession on Android, a no-op stub

backend/config/config.go

@@ -303,24 +303,6 @@ func (c *Config) GetLibraryDirectory() string {
 	return string(c.Library.DirectoryPath)
 }
 
-// A rejected setter puts the old value back, and that is not tidiness
-// (#231).  Save validates the *whole* config, so a value left behind by
-// a failed write does not merely fail its own call: it fails every
-// later save, of every unrelated setting, silently and for the rest of
-// the session.  Nothing reaches disk, so a restart clears it -- which
-// is exactly what makes the fault hard to see and impossible to report.
-//
-// The setters below that assign and then validate therefore snapshot
-// the field first and restore it on the error path.  SetLibraryDirectory
-// is the other safe shape and the better one where the value can be
-// built on its own: it validates a candidate *before* assigning
-// anything, so there is nothing to undo.
-//
-// Not every setter needs either.  A bool, an int64 and the shortcut
-// bindings pass through no validation that can reject them, and
-// SetViewVisible refuses an unknown, non-hideable or launch-page view
-// up front, so GeneralConfig.Validate never sees one it would fail on.
-
 // SetLibraryDirectory validates and saves a new library directory,
 // then emits the LibraryConfigChanged event so listeners (e.g. the
 // Library scanner) can react.
@@ -378,14 +360,11 @@ func (c *Config) SetScanConcurrency(mode string) error {
 		c.Library.ApplyDefaults()
 	}
 
-	previous := c.Library.ScanConcurrency
 	c.Library.ScanConcurrency = library.ScanConcurrency(
 		mode,
 	)
 
 	if err := c.Library.Validate(); err != nil {
-		c.Library.ScanConcurrency = previous
-
 		return fmt.Errorf(
 			"invalid scan concurrency mode: %w", err,
 		)
@@ -476,12 +455,9 @@ func (c *Config) SetThemeAccentColor(
 		c.Theme.ApplyDefaults()
 	}
 
-	previous := c.Theme.AccentColor
 	c.Theme.AccentColor = color
 
 	if err := c.Theme.Validate(); err != nil {
-		c.Theme.AccentColor = previous
-
 		return fmt.Errorf(
 			"invalid theme accent color: %w", err,
 		)
@@ -512,12 +488,9 @@ func (c *Config) SetThemeBackgroundShade(
 		c.Theme.ApplyDefaults()
 	}
 
-	previous := c.Theme.BackgroundShade
 	c.Theme.BackgroundShade = theme.BackgroundShade(shade)
 
 	if err := c.Theme.Validate(); err != nil {
-		c.Theme.BackgroundShade = previous
-
 		return fmt.Errorf(
 			"invalid theme background shade: %w", err,
 		)
@@ -571,12 +544,9 @@ func (c *Config) SetDefaultPage(page string) error {
 		c.General.ApplyDefaults()
 	}
 
-	previous := c.General.DefaultPage
 	c.General.DefaultPage = View(page)
 
 	if err := c.General.Validate(); err != nil {
-		c.General.DefaultPage = previous
-
 		return fmt.Errorf(
 			"invalid default page: %w", err,
 		)
@@ -621,12 +591,9 @@ func (c *Config) SetQueueFallback(mode string) error {
 		c.General.ApplyDefaults()
 	}
 
-	previous := c.General.QueueFallback
 	c.General.QueueFallback = QueueFallback(mode)
 
 	if err := c.General.Validate(); err != nil {
-		c.General.QueueFallback = previous
-
 		return fmt.Errorf(
 			"invalid queue fallback: %w", err,
 		)
@@ -834,12 +801,9 @@ func (c *Config) SetTrackListColumns(
 		c.TrackList = &tracklist.Config{}
 	}
 
-	previous := c.TrackList.Columns
 	c.TrackList.Columns = columns
 
 	if err := c.TrackList.Validate(); err != nil {
-		c.TrackList.Columns = previous
-
 		return fmt.Errorf(
 			"invalid track-list columns: %w", err,
 		)
@@ -937,12 +901,9 @@ func (c *Config) SetFavoritesIconStyle(
 		c.Favorites.ApplyDefaults()
 	}
 
-	previous := c.Favorites.IconStyle
 	c.Favorites.IconStyle = favorites.IconStyle(style)
 
 	if err := c.Favorites.Validate(); err != nil {
-		c.Favorites.IconStyle = previous
-
 		return fmt.Errorf(
 			"invalid favorites icon style: %w", err,
 		)

backend/config/setter_rollback_test.go

@@ -1,262 +0,0 @@
-package config
-
-import (
-	"log/slog"
-	"path/filepath"
-	"testing"
-
-	"yellowjacket/backend/library"
-	"yellowjacket/backend/tracklist"
-)
-
-// newSavableConfig builds a loaded, valid config in a temp directory,
-// so Save() writes rather than refusing with errSaveBeforeLoad.
-//
-// The library directory is real and set, because Config.Validate only
-// validates the Library section when DirectoryPath is non-empty -- an
-// empty one would hide a poisoned ScanConcurrency from the whole-config
-// save that is the symptom under test.
-func newSavableConfig(t *testing.T) *Config {
-	t.Helper()
-
-	c := &Config{
-		logger:   slog.Default(),
-		filePath: filepath.Join(t.TempDir(), "config.toml"),
-		Library: &library.Config{
-			DirectoryPath: library.Directory(t.TempDir()),
-		},
-	}
-
-	c.applyDefaults()
-
-	if err := c.Load(); err != nil {
-		t.Fatalf("Load() error: %v", err)
-	}
-
-	if err := c.Save(); err != nil {
-		t.Fatalf("Save() on a fresh config error: %v", err)
-	}
-
-	return c
-}
-
-// TestSetterRejectionDoesNotPoisonTheConfig is the whole of #231.
-//
-// Every setter here assigns to the in-memory config and then validates.
-// When the validation rejects the argument, the rejected value has to go
-// back -- not because the caller sees it (it gets an error either way),
-// but because Config.Save() validates the *whole* config.  A value left
-// behind by a failed setter therefore fails every later save, of every
-// unrelated setting, silently and for the rest of the session.
-//
-// So each case asserts three things in order: the setter reports the
-// error, the getter still reports the old value, and an unrelated save
-// still works.  The third is the one the user feels.
-func TestSetterRejectionDoesNotPoisonTheConfig(t *testing.T) {
-	t.Parallel()
-
-	cases := []struct {
-		name string
-		// reject calls the setter with an argument its own Validate
-		// refuses.
-		reject func(*Config) error
-		// read reports the value the setter writes, so the rollback is
-		// asserted on the config rather than only on the save.
-		read func(*Config) string
-	}{
-		{
-			name: "scan concurrency",
-			reject: func(c *Config) error {
-				return c.SetScanConcurrency("telepathy")
-			},
-			read: (*Config).GetScanConcurrency,
-		},
-		{
-			name: "theme accent colour",
-			reject: func(c *Config) error {
-				return c.SetThemeAccentColor("not-a-hex")
-			},
-			read: (*Config).GetThemeAccentColor,
-		},
-		{
-			name: "theme background shade",
-			reject: func(c *Config) error {
-				return c.SetThemeBackgroundShade("chartreuse")
-			},
-			read: (*Config).GetThemeBackgroundShade,
-		},
-		{
-			name: "default page",
-			reject: func(c *Config) error {
-				return c.SetDefaultPage("nowhere")
-			},
-			read: (*Config).GetDefaultPage,
-		},
-		{
-			name: "queue fallback",
-			reject: func(c *Config) error {
-				return c.SetQueueFallback("improvise")
-			},
-			read: (*Config).GetQueueFallback,
-		},
-		{
-			name: "favorites icon style",
-			reject: func(c *Config) error {
-				return c.SetFavoritesIconStyle("asterisk")
-			},
-			read: (*Config).GetFavoritesIconStyle,
-		},
-		{
-			name: "track-list columns",
-			reject: func(c *Config) error {
-				// titleArtist is a drawing definition, not a
-				// configurable column (#197), so it is exactly what
-				// the frontend used to be able to send.
-				return c.SetTrackListColumns([]tracklist.Column{
-					{ID: "titleArtist"},
-				})
-			},
-			read: func(c *Config) string {
-				return columnIDs(c.GetTrackListColumns())
-			},
-		},
-		{
-			name: "track-list columns, duplicated",
-			reject: func(c *Config) error {
-				// The route #197 closed was one invalid id; a
-				// duplicate is the one still reachable from a client
-				// that assembles the list itself.
-				return c.SetTrackListColumns([]tracklist.Column{
-					{ID: tracklist.ColTrackName},
-					{ID: tracklist.ColTrackName},
-				})
-			},
-			read: func(c *Config) string {
-				return columnIDs(c.GetTrackListColumns())
-			},
-		},
-	}
-
-	for _, tc := range cases {
-		t.Run(tc.name, func(t *testing.T) {
-			t.Parallel()
-
-			c := newSavableConfig(t)
-			before := tc.read(c)
-
-			if err := tc.reject(c); err == nil {
-				t.Fatal("setter accepted an invalid value, want an error")
-			}
-
-			if after := tc.read(c); after != before {
-				t.Errorf(
-					"value after a rejected write = %q, want the previous %q",
-					after, before,
-				)
-			}
-
-			// The symptom: an unrelated setting can no longer be saved.
-			if err := c.SetPopupVolume(true); err != nil {
-				t.Errorf("an unrelated setter failed after a rejected write: %v", err)
-			}
-
-			if err := c.Save(); err != nil {
-				t.Errorf("Save() failed after a rejected write: %v", err)
-			}
-		})
-	}
-}
-
-// TestRejectedSetterLeavesNothingOnDisk pairs with the sweep above: the
-// rollback must not be undone by what the file already holds, so a
-// config reloaded from disk after a rejected write agrees with memory.
-func TestRejectedSetterLeavesNothingOnDisk(t *testing.T) {
-	t.Parallel()
-
-	c := newSavableConfig(t)
-
-	if err := c.SetThemeAccentColor("#123456"); err != nil {
-		t.Fatalf("SetThemeAccentColor() error: %v", err)
-	}
-
-	if err := c.SetThemeAccentColor("not-a-hex"); err == nil {
-		t.Fatal("SetThemeAccentColor accepted a non-colour, want an error")
-	}
-
-	reloaded := &Config{logger: slog.Default(), filePath: c.filePath}
-	reloaded.applyDefaults()
-
-	if err := reloaded.Load(); err != nil {
-		t.Fatalf("Load() error: %v", err)
-	}
-
-	if got := reloaded.GetThemeAccentColor(); got != "#123456" {
-		t.Errorf("accent colour on disk = %q, want %q", got, "#123456")
-	}
-
-	if c.GetThemeAccentColor() != reloaded.GetThemeAccentColor() {
-		t.Errorf(
-			"in-memory accent %q disagrees with disk %q after a rejected write",
-			c.GetThemeAccentColor(), reloaded.GetThemeAccentColor(),
-		)
-	}
-}
-
-// TestSetLibraryDirectoryValidatesBeforeAssigning pins the precedent the
-// seven rolled-back setters follow: this one has always built and
-// validated a candidate before assigning, so a bad path never reaches
-// the config at all.
-func TestSetLibraryDirectoryValidatesBeforeAssigning(t *testing.T) {
-	t.Parallel()
-
-	c := newSavableConfig(t)
-	before := c.GetLibraryDirectory()
-
-	if err := c.SetLibraryDirectory(filepath.Join(t.TempDir(), "no-such-dir")); err == nil {
-		t.Fatal("SetLibraryDirectory accepted a missing directory, want an error")
-	}
-
-	if after := c.GetLibraryDirectory(); after != before {
-		t.Errorf("library directory = %q, want the previous %q", after, before)
-	}
-
-	if err := c.Save(); err != nil {
-		t.Errorf("Save() failed after a rejected library directory: %v", err)
-	}
-}
-
-// TestSetViewVisibleRefusesBeforeAssigning covers the other setter left
-// out of the rollback pass: it guards its own argument up front, so
-// GeneralConfig.Validate never sees a view it would reject.
-func TestSetViewVisibleRefusesBeforeAssigning(t *testing.T) {
-	t.Parallel()
-
-	c := newSavableConfig(t)
-
-	if err := c.SetViewVisible("no-such-view", false); err == nil {
-		t.Fatal("SetViewVisible accepted an unknown view, want an error")
-	}
-
-	if err := c.SetViewVisible(c.GetDefaultPage(), false); err == nil {
-		t.Fatal("SetViewVisible hid the launch page, want an error")
-	}
-
-	if err := c.Save(); err != nil {
-		t.Errorf("Save() failed after a refused view visibility change: %v", err)
-	}
-}
-
-// columnIDs renders a column list for comparison in the table above.
-func columnIDs(cols []tracklist.Column) string {
-	ids := make([]byte, 0, len(cols)*8)
-
-	for i, col := range cols {
-		if i > 0 {
-			ids = append(ids, ',')
-		}
-
-		ids = append(ids, col.ID...)
-	}
-
-	return string(ids)
-}