Adds cleanup handlers to release held file locks when the process
terminates via SIGTERM, SIGINT, or normal exit. This prevents orphaned
lock files that would block future sessions.
Fixes#1951
What:
- stub resolvePinnedHostname in web-fetch tests to avoid DNS flake
- close lock file handles via FileHandle.close during cleanup to avoid EBADF
Why:
- make CI deterministic without network/DNS dependence
- prevent double-close errors from GC
Tests:
- pnpm vitest run --config vitest.unit.config.ts src/agents/tools/web-tools.fetch.test.ts src/agents/session-write-lock.test.ts (failed: missing @aws-sdk/client-bedrock)
Adds process exit handlers to release all held session locks on:
- Normal process.exit() calls
- SIGTERM / SIGINT signals
This ensures locks are cleaned up even when the process terminates
unexpectedly, preventing the 'session file locked' error.
