feat(ProcessManager): add Bun availability check and improve PID file validation

- Implemented a method to check if Bun is available in the system PATH.
- Updated the startWithBun method to return an error if Bun is not found.
- Enhanced PID file parsing to validate required fields and their types.
- Cleaned up stale PID files if the process is no longer alive.

fix(SettingsRoutes): clear port cache after updating settings

- Added a call to clearPortCache after writing updated settings to ensure the application uses the latest configuration.

README.md

@@ -109,7 +109,7 @@ npx mintlify dev
 - **[Architecture Evolution](https://docs.claude-mem.ai/architecture-evolution)** - The journey from v3 to v5
 - **[Hooks Architecture](https://docs.claude-mem.ai/hooks-architecture)** - How Claude-Mem uses lifecycle hooks
 - **[Hooks Reference](https://docs.claude-mem.ai/architecture/hooks)** - 7 hook scripts explained
-- **[Worker Service](https://docs.claude-mem.ai/architecture/worker-service)** - HTTP API & PM2 management
+- **[Worker Service](https://docs.claude-mem.ai/architecture/worker-service)** - HTTP API & Bun management
 - **[Database](https://docs.claude-mem.ai/architecture/database)** - SQLite schema & FTS5 search
 - **[Search Architecture](https://docs.claude-mem.ai/architecture/search-architecture)** - Hybrid search with Chroma vector database
 
@@ -149,7 +149,7 @@ npx mintlify dev
 
 1. **5 Lifecycle Hooks** - SessionStart, UserPromptSubmit, PostToolUse, Stop, SessionEnd (6 hook scripts)
 2. **Smart Install** - Cached dependency checker (pre-hook script, not a lifecycle hook)
-3. **Worker Service** - HTTP API on port 37777 with web viewer UI and 10 search endpoints, managed by PM2
+3. **Worker Service** - HTTP API on port 37777 with web viewer UI and 10 search endpoints, managed by Bun
 4. **SQLite Database** - Stores sessions, observations, summaries with FTS5 full-text search
 5. **mem-search Skill** - Natural language queries with progressive disclosure (~2,250 token savings vs MCP)
 6. **Chroma Vector Database** - Hybrid semantic + keyword search for intelligent context retrieval
@@ -263,7 +263,7 @@ See [CHANGELOG.md](CHANGELOG.md) for complete version history.
 
 - **Node.js**: 18.0.0 or higher
 - **Claude Code**: Latest version with plugin support
-- **PM2**: Process manager (bundled - no global install required)
+- **Bun**: JavaScript runtime and process manager (auto-installed if missing)
 - **SQLite 3**: For persistent storage (bundled)
 
 ---