v0.4.1: Focus Hardening & Concurrency Resilience

Fixed

• Focus Cancellation Ownership & Actor Reentrancy (F-01):
  • Associated active cancellation handlers with monotonic generation IDs, preventing superseded navigation requests from clearing newer cancellation handlers upon actor reentrancy.
  • Ensured prompt cooperative cancellation propagation to child worker tasks upon arrival of newer navigation requests.
• Deterministic LaunchServices Fallback & Main-Thread Safety (F-02):
  • Added non-blocking asynchronous fallback via NSWorkspace.openApplication when direct AppKit activation fails.
  • Synchronous fallback path explicitly avoids blocking the main thread on semaphores to eliminate UI deadlocks.
• TimeoutCoordinator Concurrency State Machine:
  • Strict thread-safe state transitions guarded by NSLock.
  • Guarantees continuations resume at most once, captures continuations and tasks under lock, and executes resumptions and task cancellations outside the lock.
  • Automatically purges child task handles upon reaching terminal completion to prevent retain cycles.
• Menu Bar Session Stability:
  • Freezes recent session ordering into an immutable snapshot upon menu opening, preserving stable keyboard shortcuts (⌘1–⌘9).
• Adapter Precedence:
  • Enforced stable FIFO ordering for specialized application adapters with GenericApplicationAdapter pinned at baseline priority.

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