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>

shared/infrastructure/factory.py

@@ -72,6 +72,7 @@ def create_base_app(
         static_folder=STATIC_DIR,
         static_url_path="/static",
         template_folder=TEMPLATE_DIR,
+        root_path=str(BASE_DIR),
     )
 
     configure_logging(name)