v0.1.4: playback-control provenance log

LinTunes has spontaneously resumed playback for ~4s (then paused) four
times while trav was away — suspected phantom media-key events from the
Audioengine USB DAC's HID 'keyboard', but the pathway (MPRIS vs the
focused-window key filter) is unproven. Every control path now drops a
timestamped line in ~/.cache/lintunes/control-events.log: MPRIS Player
methods, the media-key eventFilter (with source input device where the
compositor exposes it), and Player.toggle_play/pause with position. New
lintunes/eventlog.py, 1MB rotation, never raises; conftest autouse
fixture keeps tests off the real log file.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

TASKS.md

@@ -3,6 +3,28 @@
 Legend: `[ ]` todo · `[~]` in progress · `[x]` done.
 When a round closes, move its finished items to `tasks-done.md`.
 
+## Round 23 — playback-control provenance log (v0.1.4)
+
+Tests in `tests/test_round23.py`. Diagnostic round → patch bump **0.1.4**.
+
+Background: LinTunes has resumed playback by itself for ~4s (then paused)
+four times while trav was away/asleep (Jul 5, 7, 8?, 10). Fingerprint each
+time: current track resumed from its paused position, paused ~4s later.
+Suspected phantom media-key events (the Audioengine 2+ USB DAC registers a
+HID *keyboard*), but the pathway is unproven — hence instrumentation.
+
+- [x] New `lintunes/eventlog.py` — `log_control(source, action, detail)`
+      appends timestamped one-liners to
+      `~/.cache/lintunes/control-events.log` (1 MB rotate, never raises)
+      and mirrors to the `lintunes.control` logger.
+- [x] Provenance hooks: every MPRIS Player method (`mpris.py`; PyQt6 lacks
+      QDBusContext so no sender — run dbus-monitor alongside when the
+      sender matters), the media-key `eventFilter` in `main_window.py`
+      (logs the source input device where the compositor exposes it), and
+      `Player.toggle_play`/`pause` (state + position).
+- [x] `tests/conftest.py`: autouse fixture isolates the log path so tests
+      never write the real ~/.cache file.
+
 ## Round 22 — start time honored on same-source replay (v0.1.3)
 
 Plan reference: `~/.claude/plans/could-you-look-into-generic-balloon.md`.