feat: scaffold Brain of Reese — FastAPI RAG chat over Postgres 17 + pgvector

Foundation (phase 01, verified):
- FastAPI app: /api/health, /api/suggestions, /api/chat (placeholder),
  static frontend served locally (no CDN)
- Postgres 17 + pgvector via db/Containerfile + compose.yaml
  (podman compose up -d db), Alembic initial migration (documents,
  chunks with vector(768), query_log)
- LLM client targeting https://aipi.reeseapps.com/v1 (turbo/embed);
  scripts/llm_probe.py verified models + 768-dim embeddings live
- Conditional debugpy: imported only when DEBUGPY=1 (attach on demand,
  :5678); logging config for clean single-line logs
- Frontend shell: mobile-first chat + Sources pages, tokens, a11y baselines
- Tests: 24 unit+integration (99% coverage on app/), ruff + pyright clean,
  Playwright smoke E2E (3 tests) against a deterministic mock LLM
- Planning: .agent/PLAN.md (architecture + LOCKED decisions), AGENTS.md,
  6 user stories, 7 phase files (one story / one phase / one Playwright
  suite each)

.agent/phases/todo/01_infrastructure.md

@@ -0,0 +1,59 @@
+# Phase 01 — Infrastructure Foundation
+
+**Story:** — (foundation; no user story)
+**Context:** `.agent/PLAN.md` §2–§5, §8–§10 · `AGENTS.md`
+
+## Goal
+A verified, reproducible foundation: environment installs, Postgres 17 +
+pgvector running via `podman compose up -d db`, migrations applied, app
+booting with `/api/health`, lint/types clean, and the smoke E2E green.
+The scaffolding already exists in the repo — this phase **verifies and
+completes** it (fix gaps rather than rewrite).
+
+## Implementation steps
+1. `uv sync` — confirm all deps resolve from `uv.lock`.
+2. `podman compose up -d db` — build the `db/` image (postgres:17 +
+   pgvector) and start the container; `podman compose ps` must show
+   `healthy`.
+3. `uv run alembic upgrade head` — schema applied (`documents`, `chunks`,
+   `query_log`, `vector` extension). Verify with
+   `psql -h localhost -U reese -d brain_of_reese -c '\d chunks'`
+   (embedding column `vector(768)`).
+4. `uv run python -m scripts.llm_probe` — live aipi check: `turbo` + `embed`
+   present, dim 768. (If the endpoint is unreachable, record it and continue;
+   E2E uses the mock.)
+5. `DEBUGPY=0 uv run uvicorn app.main:app` boots and serves `/`,
+   `/api/health`, `/api/suggestions` (Ctrl-C to stop). Also verify
+   `DEBUGPY=1` prints the debugpy listen warning and the app stays
+   responsive.
+6. Fix anything broken in scaffold files (keep PLAN-conformant).
+
+## Testing & Quality
+- Unit + integration: `uv run pytest` — green.
+- Coverage: `uv run pytest --cov=app --cov-report=term-missing` — record the
+  number; the >90% gate is enforced from the first feature phase onward
+  (skeleton coverage should already be high).
+- Lint/types: `uv run ruff check .` and `uv run pyright` — zero errors.
+
+## Playwright Execution Phase
+Run ONLY the smoke suite (verify the browser is installed first —
+`uv run playwright install chromium` if missing):
+
+```bash
+uv run pytest tests/e2e/test_smoke.py -v --no-cov
+```
+
+Expected: 3 passed (health, index page, placeholder round-trip).
+
+## Success criteria
+- [ ] `podman compose up -d db` → healthy
+- [ ] `alembic upgrade head` clean; `vector(768)` column present
+- [ ] app boots; `/api/health` `db: up`
+- [ ] unit + integration green; ruff + pyright clean
+- [ ] smoke E2E green in isolation
+- [ ] committed (see below)
+
+## Commit
+```bash
+git add -A && git commit --no-gpg-sign -m "chore(infra): verify foundation — pg17+pgvector, migrations, debugpy gating, smoke E2E"
+```