docs(player): attribute the phone seek bar's removal correctly

The paragraph said #59 took the seek bar off the phone's transport.
It was plan 016 B2 — audio-player.ts says so in the comment above the
rule that does it, and CLAUDE.md's own #59 paragraph says #59 removed
shuffle, repeat and the queue button. Wrong provenance in the file
whose whole value is being right about which change did what.

Also stop tracking .pi/journal.md. It is a scheduled run's scratch log,
and this repo's memory is CLAUDE.md and .planning/ — a session log
arriving inside a feature PR is a new convention landing sideways.

.pi/journal.md

@@ -1,38 +0,0 @@
-# Journal
-
-Running work log: what was done, what was verified, what was left open.
-Newest entry last.
-
-## 2026-08-21 — #58, the phone's progress line
-
-Took #58 (Phase 3, item 4 of the roadmap in #73; #56 and #59 landed
-before it and #64 after, so this was the phase's remaining item ahead of
-#51's verification pass). Branch `feat/58-mini-player-progress-line`.
-
-**What.** `<player-progress-line>` in the shell, with its own `auto`
-grid row between `bottom-bar` and `bottom-nav` below 600px. 2px, the
-fill is `scaleX()` off `PlaybackPositionChanged` with the seek bar's
-`trackChangeId`/`seq` guards and an interval that only interpolates
-between reports. `aria-hidden`, `pointer-events: none`, and it renders
-nothing above 600px or with no track.
-
-**Verified.**
-
-- `make ui-test` — 992 passed, including 8 new in
-  `frontend/test/components/progress-line.test.ts` (the matchMedia
-  branch, the report/interpolation rules, paused, a stale report, and
-  that it is neither announced nor touchable).
-- `make e2e --project=chromium` — 223 passed, including 3 new in
-  `e2e/specs/phone-progress-line.spec.ts` (the two adjacencies, that it
-  takes no taps, that it is absent on a desktop). WebKit is CI's half;
-  Arch cannot run Playwright's Linux WebKit.
-- Read a screenshot at the reference device's 424x439 with a real track
-  playing, and watched the real transform advance 0.288889 -> 0.377778
-  over 8 s of a 90 s track. Also checked the line goes with the bar on
-  `now-playing`.
-- No Go changed, so `make lint`/`make test` were not run.
-
-**Left open.** No device tier: this is a browser at 424x439, which
-`CLAUDE.md` is explicit is not a phone. The line's *appearance* on
-Chrome 113 is unverified; the CSS it uses (a transform and a flat
-background) is nowhere near that engine's gaps.