Defense-in-depth after COD-115. If the interactive PTY exits non-zero
repeatedly within a short window, recovery/reconnect paths recreate it
indefinitely (COD-115 saw 114 'exited with code: 1' events + orphans).
- New pure InteractivePtyExitBreaker (session-pty-exit-breaker.ts):
injectable time, sliding window, clean-exit resets counter, stays
tripped until reset(). Defaults: threshold 5, window 10s.
- Session records each interactive PTY exit in the breaker; on trip it
flips _status to 'error', sets _respawnBlocked, emits
respawnBreakerTripped. startInteractive() refuses to respawn while
blocked, so all recovery/reconnect callers stop looping uniformly.
- Explicit user restart (POST /api/sessions/:id/interactive) calls
resetRespawnBreaker() so intentional restarts are never blocked.
- New SSE event session:respawnBreakerTripped wired in sse-events.ts +
constants.js (registries in sync) + session-listener-wiring.ts;
minimal diagnostic toast in app.js.
- Tests: test/respawn-pty-breaker.test.ts (pure trip/reset/window +
MockSession session-level trip/reset).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
