PLN, after the value ramp landed: "now all knobs have lights, i cant trust
anymore 'is there sth mapped there or not?' knobs should always be no-lit if they
are not-mapped, in that track, to help not touch dead controls".

The interesting part is that the colour code was never wrong. build_frame()
already paints only the CCs present in `bindings` and leaves everything else OFF.
The lie was in WHICH BINDINGS IT WAS HANDED: the watcher runs with no track
argument, so load_bindings(None) returns the CONVENTION board — all 40 controls
lit by lane role, regardless of what is actually loaded. That was equally untrue
before the ramp; dim role-hue just made it easy to ignore, and saturated colour
made the board finally READ as "everything here is live".

So the feature did not create the problem, it made a pre-existing lie legible —
and fixing the colour back would have hidden the fault again.

MEASURED:
    convention board (what the watcher painted)   40/40 lit
    do_it_right                                   19/40   -> 21 dead knobs lit
    wap                                           25/40   -> 15
    desire                                        22/40   -> 18
Fifteen to twenty-one controls were glowing on every track while doing nothing.
On a dark stage that is a knob you reach for and a change you do not get.

The fix is a published current-track file (~/.cache/parvagues/current-track):
  * `--map TRACK` now PUBLISHES as well as paints. Without that, a one-shot paint
    at boot showed the right board for 30 seconds and then the watcher's re-assert
    overwrote it with the convention paint — the same board, lying again. One
    writer, one meaning.
  * `--watch` with no pinned track follows the file on a 1s poll and repaints on
    change. Polled rather than inotify on purpose: a watch that dies unnoticed is
    exactly this rig's signature failure (a binding resolved once, never
    rechecked), and one stat/second of a small file costs nothing measurable.
  * touched-state clears on track change (carrying it would claim you had already
    worked controls on a track you just opened); VALUES persist, because the knobs
    did not physically move.
  * bindings moved into a shared box — three reads in the aseqdump loop and the
    re-assert thread would otherwise have kept painting the previous track's map.

load_bindings(None) now also SAYS it is painting a board that may be lying,
instead of reporting "40 controls lit by lane role" as though that were good news.

The remaining gap, deliberately not closed here: nothing publishes the track when
PLN ctrl+enters a file in Pulsar — only `tidal-remote boot` does. The clean signal
is a five-line hook in the HUD package, which already tracks the active .tidal.
Filed rather than rushed the day before rehearsals.

458 tests (was 453). NOTE: the running watcher must be RESTARTED to pick this up;
not done now, because PLN is about to play and a dark board mid-set beats a
correct board that arrived by surprise.