Auto-Ingestion Watch Daemon

[ashu17706]

What

A `smriti watch` command that monitors agent log directories via `fs.watch()` and auto-ingests new/changed sessions in real-time.

Why

Currently ingestion is manual (`smriti ingest claude`). Developers forget to run it, or run it too late after context is cold. Auto-ingestion means Smriti always has the latest session data available for search and recall.

Tasks

• Implement `smriti watch` CLI command with graceful start/stop
• Use `fs.watch()` (or Bun's equivalent) to monitor `~/.claude/projects/` and other agent log dirs
• Debounce file change events (JSONL files get appended to frequently during active sessions)
• Incremental ingestion: track file size/mtime, only re-parse appended content
• Handle session file rotation (new session creates new file)
• PID file at `~/.smriti/watch.pid` for single-instance enforcement
• `smriti watch --daemon` for background mode (detached process)
• `smriti watch --stop` to kill running daemon
• `smriti watch --status` to check if daemon is running
• Optional auto-embed: trigger embedding generation after ingestion
• Optional auto-categorize: trigger categorization after ingestion
• Configurable debounce interval via `SMRITI_WATCH_DEBOUNCE_MS` (default: 2000)

Files

• `src/watch.ts` — new Watch daemon implementation
• `src/index.ts` — Add `watch` command to CLI
• `src/config.ts` — Add watch-related config vars
• `test/watch.test.ts` — new Watch daemon tests (using temp directories)

Acceptance Criteria

• `smriti watch` starts monitoring and logs ingestion events
• New Claude sessions appear in `smriti search` within seconds of creation
• Appending to existing session files triggers incremental re-ingestion
• Only one watch daemon runs at a time (PID file enforcement)
• `smriti watch --stop` cleanly terminates the daemon
• CPU usage stays below 1% when idle (no busy polling)
• Handles agent log directory not existing (waits for creation)

Testing

bun test test/watch.test.ts    # Unit tests with temp dirs
smriti watch                   # Manual: start watching
# In another terminal, use Claude Code — sessions should auto-ingest
smriti watch --status          # Check daemon status
smriti watch --stop            # Stop cleanly