perf(entity): scope availability subscription to the lock entities

[terafin]

Proposed change

The availability binary_sensor registers its state-change handler with all_states=True:

async_track_state_change_filtered(
    self.hass, TrackStates(True, set(), set()), self._handle_available_state_update
)

TrackStates(True, ...) subscribes to every state change in the entire Home Assistant instance. _handle_available_state_update then filters in Python and early-returns for any entity that isn't one of the slot's locks.

On a production instance with ~6–7 of these entities, cProfile measured the handler running ~86,580 times / 30s (~2,900/sec) and its inner generator ~640,100 times / 30s — the single largest application-level CPU consumer, doing no useful work.

Fix

Scope the subscription to just the lock entities:

TrackStates(False, {lock.lock.entity_id for lock in self.locks}, set())

self.locks is mutated at runtime (_handle_add_locks / _handle_remove_lock), so the tracked set is re-scoped via async_update_listeners() whenever locks change, and availability is recomputed at that point — previously the all-states firehose recomputed it implicitly, so this preserves behavior for the dynamic add/remove-lock case. The initial availability computation and the async_on_remove cleanup are unchanged.

Pure performance fix; no behavior change. Verified: the full test_binary_sensor.py, test_event.py, and test_callbacks.py suites pass (48 tests), and a new regression test asserts the subscription is scoped to the locks and re-scopes on lock add/remove.

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New feature (which adds functionality)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• Performance regression measured via cProfile on a production HA instance running 4.2.0.
• No existing issue; filing this PR directly.

🤖 Generated with Claude Code

[codecov]

Codecov Report

❌ Patch coverage is 91.66667% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 96.94%. Comparing base (dc1ed4f) to head (b390e7d).
⚠️ Report is 13 commits behind head on main.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
custom_components/lock_code_manager/entity.py	91.66%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1306      +/-   ##
==========================================
- Coverage   96.96%   96.94%   -0.03%     
==========================================
  Files          53       53              
  Lines        6364     6374      +10     
  Branches      473      473              
==========================================
+ Hits         6171     6179       +8     
- Misses        193      195       +2     

Flag	Coverage Δ
python	97.47% <91.66%> (-0.04%)	⬇️

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Files with missing lines	Coverage Δ
custom_components/lock_code_manager/entity.py	94.89% <91.66%> (-1.18%)	⬇️

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[raman325]

thanks for the contribution! Only one question/comment

[raman325]

not sure if this guard is necessary, I believe by this point the tracker will be set