chore: Step 0 — purge TS monorepo per plan-v4 (Python rewrite complete)

Removes the pre-Python-rewrite TypeScript implementation in full. All domain
functionality has been re-implemented in Python under my-deepagent/ (Step 1~15,
579 unit/integration tests + 1 real-OpenRouter E2E PASS).

Deleted directories (4):
- apps/      — TS api/cli/web/worker apps; replaced by my-deepagent/src/my_deepagent/cli/
- packages/  — TS core/db/run-engine/session/workflows packages; replaced by my-deepagent/src/my_deepagent/{config,enums,persona,workflow,binding,persistence,engine,session,…}
- tests/     — TS workspace smoke tests + fixtures; replaced by my-deepagent/tests/{unit,integration}/
- scripts/   — migrate.ts, seed.ts; replaced by my-deepagent alembic + persistence/db.py

Deleted files (10):
- pnpm-lock.yaml, pnpm-workspace.yaml, package.json
- biome.json, lefthook.yml, vitest.workspace.ts, drizzle.config.ts
- tsconfig.base.json, tsconfig.json, tsconfig.typecheck.json
- .nvmrc

Recovery point:
- Tag `pre-python-rewrite` at c9fed71 — `git checkout pre-python-rewrite -- <path>`
  retrieves any historical TS file if ever needed.

Preserved (per plan-v4-draft.md):
- docs/                      — plan.md (v3 r13, will be patched to v4 r1 next), schemas/
- docker-compose.yml         — Postgres + Temporal containers (still relevant for M5)
- .env.example               — base env contract
- my-deepagent/              — Python implementation
- my-deepagent-seed/         — v0.1.0 bootstrap kit (PoC + seed yaml/json), kept as
                               historical reference; pruning is a separate decision.

.gitignore rewritten for Python-only project (.venv, __pycache__, *.sqlite3, …)
with Node entries dropped.

--no-verify: lefthook (TS-only) was just deleted with this commit.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.gitignore

@@ -1,12 +1,30 @@
-node_modules/
-dist/
-coverage/
-.turbo/
 .DS_Store
 .env
 .env.local
 .env.*.local
 *.log
-*.tsbuildinfo
 data/
 !.gitkeep
+
+# Python
+__pycache__/
+*.py[cod]
+*$py.class
+.venv/
+.python-version
+*.egg-info/
+.pytest_cache/
+.ruff_cache/
+.mypy_cache/
+.coverage
+htmlcov/
+
+# Build / IDE
+dist/
+build/
+.idea/
+.vscode/
+
+# SQLite local
+*.sqlite3
+*.sqlite3-journal