First implementation pass of the cognee-watcher per DESIGN.md. Parked pending the Cognee deployment so we don't lose the work.

Scope

• src/cognee_watcher/ modules: config (pydantic-settings env validation), log (JSON structured logs), encoding (path↔name bijection: _ → _U, / → __), client (async REST wrapper with tenacity retries on 5xx / 429 / transport errors), watcher (awatch loop, debounce, op routing, single cognify per burst), reconcile (boot + periodic drift-repair sweep), main (CLI entry, SIGTERM handling, wiring).
• tests/ — 27 tests via pytest + respx (HTTP mocking) + in-memory fake client. Encoding round-trips, REST client error paths, watcher routing (add / update / delete / batch / ignore-globs / collapse).
• pyproject.toml (hatchling, deps: httpx, watchfiles, tenacity, pydantic-settings, python-json-logger), Dockerfile, .env.example, README.md quickstart.

Verified locally

• pytest -q → 27 passed
• ruff check . → clean
• cognee-watcher boots and hard-fails with a clear error on missing required env

Not yet verified (blocks merge)

• End-to-end against a real Cognee instance — deployment is WIP. Open assumptions to confirm once it's up:
  • GET /api/v1/datasets/{ds}/data?name=… filters server-side (client falls back to scanning anyway)
  • PATCH /api/v1/update accepts dataId + datasetId as multipart form fields alongside the file
  • Response payload shape for /add / /update / /data (current code tolerates both raw list and {data: […]} envelope)

Done when

• A real Cognee instance is reachable from a test container, an add → modify → delete cycle is observed end-to-end, and the corresponding entities/edges appear / supersede / vanish in the dataset.