ci: integration tests on PostgreSQL + pgvector for migrations and store SQL

New `ci / db` job with a pgvector service: Go applies all migrations,
rolls them back to zero and applies them again, then runs the scanner,
fingerprint, write-template, top-tracks and upload-queue store queries;
Python runs the analysis worker, catalog / profile loading and a full
ALS training run against the same schema. Until now this SQL ran
nowhere before reaching a real server.

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

.gitea/workflows/ci-db.yml

@@ -0,0 +1,52 @@
+# Интеграционные проверки SQL на настоящем PostgreSQL + pgvector: миграции вверх / вниз / вверх,
+# запросы сканера, отпечатков, шаблонов и очереди (Go), загрузка каталога, профиля и обучение ALS (Python).
+name: ci / db
+
+on:
+  push:
+    branches: [main]
+    paths:
+      - 'services/api/**'
+      - 'services/recommender/**'
+      - '.gitea/workflows/ci-db.yml'
+  pull_request:
+    paths:
+      - 'services/api/**'
+      - 'services/recommender/**'
+      - '.gitea/workflows/ci-db.yml'
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  db:
+    runs-on: ubuntu-latest
+    services:
+      postgres:
+        image: pgvector/pgvector:0.8.7-pg17
+        env:
+          POSTGRES_USER: pipu
+          POSTGRES_PASSWORD: pipu
+          POSTGRES_DB: pipu
+        options: >-
+          --health-cmd "pg_isready -U pipu"
+          --health-interval 5s
+          --health-timeout 5s
+          --health-retries 20
+    env:
+      TEST_DATABASE_URL: postgres://pipu:pipu@postgres:5432/pipu?sslmode=disable
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with: { go-version: "1.24", cache-dependency-path: services/api/go.sum }
+      - name: Go — миграции и запросы store
+        working-directory: services/api
+        run: go test -tags integration -count=1 -v ./internal/dbtest/
+      - uses: astral-sh/setup-uv@v6
+        with: { version: "0.10.2", enable-cache: true, cache-dependency-glob: services/recommender/uv.lock }
+      - name: Python — каталог, профиль, обучение ALS
+        working-directory: services/recommender
+        run: |
+          uv sync --frozen
+          uv run pytest -q tests/test_db_integration.py