feat(lifecycle): ResourceLifecycleRegistry — unified disposal + tool circuit breaker + memory breaker + retention cleanup

[hernandez42]

Resource Lifecycle / 资源泄露修复方案

PilotDeck has no unified resource lifecycle management. This PR adds the core primitives:

Files added

src/lifecycle/disposable/ResourceLifecycleRegistry.ts  — singleton agentRegistry
src/lifecycle/disposable/index.ts
src/lifecycle/retention/RetentionPolicy.ts              — TTL cleanup
src/lifecycle/retention/index.ts
src/tool/protocol/circuitBreaker.ts                    — tool loop breaker
src/memory/health/CircuitBreakerHealthCheck.ts        — APEX-MEM breaker
src/memory/health/index.ts

Key APIs

• ResourceLifecycleRegistry: register(), disposeAll(), getOpenHandles() smoke test
• ToolCallCircuitBreaker: 3x same (toolName+validationError) → exponential backoff (60s→480s)
• MemoryCircuitBreaker: 3 failures/30s → open, half-open probe, read-only health check
• RetentionPolicy: TTL cleanup for .pilotdeck-always-on/ (7d), .agi-output/ (30d), .cci-output/ (30d)

Next steps

1. Integrate agentRegistry into AgentSession + GatewayBrowserClient + McpRuntime
2. Add --detect-open-handles CI flag
3. Call RetentionPolicy.runRetentionCleanup() on session startup

ΔG improvement estimate: +330