fix(daemon): fix locking module bugs (GREEN phase)

[galligan]

• isProcessAlive now validates negative PIDs before process.kill()
• releaseDaemonLock now properly unlinks file instead of clearing

All 23 locking tests pass.

Co-Authored-By: Claude Opus 4.5 noreply@anthropic.com

Contributes to #56

[galligan]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
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• chore(outfitter): sync templates on pack #108
• chore(changesets): ignore app package #107
• fix(errors): avoid TaggedError extends warnings #106
• chore(release): align package versions to 0.1.0 #105
• docs: add README and CHANGELOG for testing, kit, outfitter #95
• feat(templates): add daemon project template #94
• feat(templates): add MCP server project template #93
• feat(templates): add CLI project template #92
• fix(cli): implement confirmDestructive prompts #104
• fix(cli): implement createCLI and command builder #103
• feat(kit): add @outfitter/kit meta-package #91
• docs(daemon): add README and CHANGELOG #90
• fix(daemon): fix locking module bugs (GREEN phase) #89 👈 (View in Graphite)
• test(daemon): add locking module tests (RED phase) #88
• feat(daemon): add errors, platform, and locking module stubs #87
• feat(outfitter): add doctor command for environment validation #86
• feat(outfitter): add init command with project scaffolding #85
• feat(daemon): add IPC communication and health checks #84
• feat(daemon): add types and lifecycle management #83
• feat(index): add FTS5 full-text search implementation #82
• feat(index): add types for FTS5 full-text search #81
• feat(testing): add MCP and CLI test harnesses #80
• feat(testing): add test fixture utilities #79
• feat(mcp): add MCP server implementation with typed handlers #78
• feat(mcp): add types and interfaces for MCP server #77
• feat(ui): add Shape discriminated union and render() #76
• feat(ui): add createTokens semantic color layer #75
• feat(state): add pagination helpers #74
• feat(logging): add DEFAULT_PATTERNS for common secret redaction #73
• feat(ui): add formatRelative() for human-readable timestamps #72
• feat(state): add encodeCursor/decodeCursor for pagination #71
• feat(types): add hashId() for deterministic short identifiers #70
• feat(contracts): add Logger.child() and fix AssertionError category #69
• feat(config): centralize environment variable access with Zod validation #42
• fix(logging): enable redaction by default when global rules exist #41
• docs(ui): add README, CHANGELOG, and TSDoc comments #39
• docs(state): add README, CHANGELOG, and TSDoc comments #38
• docs(file-ops): add README, CHANGELOG, and TSDoc comments #37
• docs(logging): add README, CHANGELOG, and TSDoc comments #36
• docs(config): add README, CHANGELOG, and TSDoc comments #35
• fix(cli): enforce cursor TTL #114
• fix(tests): remove placeholder tests #113
• chore(gitattributes): prefer ours for bun lockfiles #115
• main

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[greptile-apps]

Greptile Summary

• Fixes critical daemon locking bugs: PID validation in isProcessAlive() and proper lock file cleanup in releaseDaemonLock()
• Updates isProcessAlive() to reject negative PIDs (which have special meaning in process.kill()) returning false for invalid process IDs
• Changes releaseDaemonLock() to properly unlink the lock file instead of just clearing its contents, ensuring complete cleanup

Important Files Changed

Filename	Overview
packages/daemon/src/locking.ts	Fixed PID validation bug and lock file cleanup bug to improve daemon lifecycle reliability

Confidence score:5/5

• This PR is safe to merge with minimal risk as it fixes clear bugs without introducing new complexity
• Score reflects targeted bug fixes with proper validation logic and improved resource cleanup handling
• No files require special attention as the changes are straightforward defensive programming improvements

Sequence Diagram

sequenceDiagram
    participant User
    participant DaemonLocking as "Daemon Locking"
    participant FileSystem as "File System"
    participant ProcessSystem as "Process System"

    User->>DaemonLocking: "acquireDaemonLock(lockPath)"
    DaemonLocking->>FileSystem: "Check if lock file exists"
    FileSystem-->>DaemonLocking: "File does not exist"
    DaemonLocking->>ProcessSystem: "Get current PID"
    ProcessSystem-->>DaemonLocking: "Return PID"
    DaemonLocking->>FileSystem: "Write PID to lock file"
    FileSystem-->>DaemonLocking: "Write successful"
    DaemonLocking-->>User: "Return LockHandle"
    
    Note over User: Daemon runs...
    
    User->>DaemonLocking: "releaseDaemonLock(handle)"
    DaemonLocking->>FileSystem: "Read lock file content"
    FileSystem-->>DaemonLocking: "Return PID content"
    DaemonLocking->>DaemonLocking: "Verify PID matches handle"
    DaemonLocking->>FileSystem: "Unlink lock file"
    FileSystem-->>DaemonLocking: "File removed"
    DaemonLocking-->>User: "Lock released"

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[galligan]

Restacked and re-submitted after downstack updates. Pre-push tests ran clean; no additional code changes on this branch.

[galligan]

Restacked after downstack updates; no additional changes beyond the rebase. Pre-push tests ran clean.

[galligan]

Restacked after downstack update (formatRelative test stabilization); no additional changes in this PR.