Decouple per-service Alembic migrations and fix cross-DB queries

Each service (blog, market, cart, events, federation, account) now owns
its own database schema with independent Alembic migrations. Removes the
monolithic shared/alembic/ that ran all migrations against a single DB.

- Add per-service alembic.ini, env.py, and 0001_initial.py migrations
- Add shared/db/alembic_env.py helper with table-name filtering
- Fix cross-DB FK in blog/models/snippet.py (users lives in db_account)
- Fix cart_impl.py cross-DB queries: fetch products and market_places
  via internal data endpoints instead of direct SQL joins
- Fix blog ghost_sync to fetch page_configs from cart via data endpoint
- Add products-by-ids and page-config-ensure data endpoints
- Update all entrypoint.sh to create own DB and run own migrations
- Cart now uses db_cart instead of db_market
- Add docker-compose.dev.yml, dev.sh for local development
- CI deploys both rose-ash swarm stack and rose-ash-dev compose stack
- Fix Quart namespace package crash (root_path in factory.py)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

federation/entrypoint.sh

@@ -10,10 +10,33 @@ if [[ -n "${DATABASE_HOST:-}" && -n "${DATABASE_PORT:-}" ]]; then
   done
 fi
 
-# Federation can optionally run migrations (set RUN_MIGRATIONS=true)
-if [[ "${RUN_MIGRATIONS:-}" == "true" ]]; then
-  echo "Running Alembic migrations..."
-  (cd shared && alembic upgrade head)
+# Create own database + run own migrations
+if [[ "${RUN_MIGRATIONS:-}" == "true" && -n "${ALEMBIC_DATABASE_URL:-}" ]]; then
+  python3 -c "
+import os, re
+url = os.environ['ALEMBIC_DATABASE_URL']
+m = re.match(r'postgresql\+\w+://([^:]+):([^@]+)@([^:]+):(\d+)/(.+)', url)
+if not m:
+    print('Could not parse ALEMBIC_DATABASE_URL, skipping DB creation')
+    exit(0)
+user, password, host, port, dbname = m.groups()
+
+import psycopg
+conn = psycopg.connect(
+    f'postgresql://{user}:{password}@{host}:{port}/postgres',
+    autocommit=True,
+)
+cur = conn.execute('SELECT 1 FROM pg_database WHERE datname = %s', (dbname,))
+if not cur.fetchone():
+    conn.execute(f'CREATE DATABASE {dbname}')
+    print(f'Created database {dbname}')
+else:
+    print(f'Database {dbname} already exists')
+conn.close()
+" || echo "DB creation failed (non-fatal), continuing..."
+
+  echo "Running federation Alembic migrations..."
+  (cd federation && alembic upgrade head)
 fi
 
 # Clear Redis page cache on deploy
@@ -28,5 +51,11 @@ print('Redis cache cleared.')
 fi
 
 # Start the app
-echo "Starting Hypercorn (${APP_MODULE:-app:app})..."
-PYTHONUNBUFFERED=1 exec hypercorn "${APP_MODULE:-app:app}" --bind 0.0.0.0:${PORT:-8000} --workers ${WORKERS:-2} --keep-alive 75
+RELOAD_FLAG=""
+if [[ "${RELOAD:-}" == "true" ]]; then
+  RELOAD_FLAG="--reload"
+  echo "Starting Hypercorn (${APP_MODULE:-app:app}) with auto-reload..."
+else
+  echo "Starting Hypercorn (${APP_MODULE:-app:app})..."
+fi
+PYTHONUNBUFFERED=1 exec hypercorn "${APP_MODULE:-app:app}" --bind 0.0.0.0:${PORT:-8000} --workers ${WORKERS:-2} --keep-alive 75 ${RELOAD_FLAG}