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.

.gitignore

@@ -88,3 +88,8 @@ build/android/overlay.json
 # Written by @semantic-release/changelog purely to carry the release notes
 # into scripts/gitea-release.sh; the release page is the changelog.
 .release-notes.md
+
+# Agent session log: local scratch, not repo memory (that is CLAUDE.md
+# and .planning/). Written by the scheduled backlog runs.
+.pi/journal.md
+.pi/schedule-prompts.json