[jamescrosswell]

Problem

When using balanced flavor, it was possible to get spurious keycodes emitted at
the start of a subsequent interaction. For example, with &ok_ltm on Y and
&kp TAB on T (on the app-switch layer), typing normally could occasionally
produce one or more T keycodes followed by the intended Y output.

Root cause: a race between the tapping-term timer and the interrupt key.

With balanced flavor, a hold is resolved when an interrupt key is both pressed
and released. However, if the tapping-term timer fires while the interrupt key
is still held down, do_hold() is called from the work handler — which sets
undecided_olm = NULL. The interrupt key's release event then arrives after
undecided_olm is NULL, so the position listener lets it bubble freely instead
of capturing it. The result: the interrupt key-down is in the capture buffer but
its key-up is not, and captured_events_count is never reset.

On the next interaction, if a tap resolves, release_captured_events() replays
the stale key-down from the previous interaction — emitting an unexpected keycode
before the intended output.

Fix

Two changes to behavior_os_layer_mod.c:

1. os_layer_mod_work_handler: call release_captured_events() immediately
   after do_hold() when the timer fires. This mirrors exactly what the
   interrupt-driven path already does in the event listener, and ensures the
   buffer is always cleared when a hold is decided.

2. on_os_layer_mod_binding_released (HOLD path): reset captured_events_count = 0
   as a defensive safety net for any edge case where an event entered the buffer
   without being replayed.

Tests

• Added tests/os-layer-mod/balanced-timer-fires-while-interrupt-held: presses
  the ok_ltm key, presses an interrupt key, then waits past tapping-term-ms
  while the interrupt key is still held. Verifies the interrupt key is replayed
  under the active layer (producing T while LALT is held), with no leakage
  into subsequent interactions.

• Fixed run-tests to run all test suites under tests/ when invoked with
  no arguments, rather than only the oskey/ suite. The os-layer-mod suite was
  previously silently skipped.