chore(devops): project skeleton — uv, docker compose, Makefile, CI

One Postgres with isolated identity/clinical databases and roles (ADR-003),
FastAPI /health, Streamlit placeholder, typed settings with offline defaults.

Refs #1

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.gitea/workflows/ci.yml

@@ -0,0 +1,21 @@
+name: CI
+
+on:
+  pull_request:
+    branches: [dev, main]
+  push:
+    branches: [dev, main]
+
+jobs:
+  lint-and-test:
+    name: ruff · pytest
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: astral-sh/setup-uv@v3
+        with:
+          version: "0.8.4"
+      - run: uv sync --frozen
+      - run: uv run ruff check .
+      - run: uv run ruff format --check .
+      - run: uv run pytest -q