Upstream macOS resilience improvements to jtroo/kanata

[malpern]

Summary

Three macOS resilience improvements were added to keypath/bundled and should be proposed upstream to jtroo/kanata once validated in production.

Changes

1. Port idle-clearing of stuck key states from Windows (c42d73a)

   • After 60s of no physical input, clears stuck keyberon normal-key states and PRESSED_KEYS
   • Mirrors the existing Windows LLHOOK clear_states_from_inactivity() mechanism
   • Addresses stuck keys caused by CPU pressure delaying release events

2. Processing loop latency canary (52e61fc)

   • Logs [LATENCY] at info level when a processing iteration takes >20ms
   • Always active, no allocation on the fast path, not platform-gated
   • Aids post-hoc diagnosis of stuck key incidents

3. Latency-triggered soft reset (85330a1)

   • After 5 consecutive slow iterations (>20ms each), clears all stuck key states
   • Releases keyberon states, PRESSED_KEYS, and tracked output keys
   • Does NOT release/regrab the HID device (no disruptive keyboard dropout)
   • macOS-only

Context

On macOS, CPU/memory pressure (compilation, Spotlight indexing) can starve the processing thread, delaying release events and leaving keys stuck. Windows already has idle-clearing for similar scenarios (Win+L lock screen). These changes extend that resilience to macOS.

Before upstreaming

• Validate in KeyPath production use (no false positives from soft reset)
• Confirm latency canary logging is not too noisy at 20ms threshold
• Consider making the soft reset threshold configurable via defcfg
• Open PR against jtroo/kanata with appropriate upstream commit messages