test: prove module database access with PostgreSQL

Add a real installed-module fixture (core/tests/fixtures/module-database-integration/db-facade)
with its own manifest, Drizzle schema, drizzle-kit-generated migration, and permissioned HTTP
routes, then exercise it end to end in a new apps/api PostgreSQL integration suite: explicit
migration application before the module runtime starts (never auto-created), start/stop/HTTP
handlers sharing one ModuleDatabase facade by reference, authorized read/mutation/transaction
commit and rollback against real PostgreSQL, denied/rejected-origin/OPTIONS/HEAD requests never
reaching the module or its table, and both a module-caught and an uncaught real database failure
sanitizing exactly as pass 1 established. Registered alongside the existing suites in
vitest.migrations.integration.config.ts; no production code, schema, or migration changed.

core/tests/fixtures/module-database-integration/db-facade/ekklesia.module.json

@@ -0,0 +1,28 @@
+{
+  "manifestVersion": 3,
+  "id": "db-facade",
+  "name": "Database Facade Integration Test Module",
+  "description": "Test-only installed module fixture proving ModuleDatabase against real PostgreSQL. Never discovered by production startup, Doctor, or normal migration aggregation — only apps/api/tests/module-database.integration.ts points discovery at it explicitly.",
+  "version": "0.1.0",
+  "compatibility": {
+    "platform": "^0.1.0",
+    "moduleSdk": "^0.1.0"
+  },
+  "permissions": [
+    {
+      "id": "db-facade.records.read",
+      "baseline": "public",
+      "description": "Read database facade test records."
+    },
+    {
+      "id": "db-facade.records.write",
+      "baseline": "authenticated",
+      "description": "Write database facade test records."
+    }
+  ],
+  "entrypoints": {
+    "server": "./server/index.js",
+    "schema": "./schema/index.js",
+    "migrations": "./drizzle"
+  }
+}