fix: address adversarial review blockers

All §1 consensus blockers and §2 high-risk gaps resolved:

Schema fixes:
- Remove RecipeIngredient join table, use JSONB for ingredients
- Add family_member table for per-voter approval tracking
- Add all ENUMs for status fields (no loose VARCHAR)
- Add CHECK constraints (household_size, rating 1-5, day_of_week)
- Add name_lower for case-insensitive ingredient matching
- Add grocery_item → ingredient FK
- Fix day_of_week to ISO-8601 (1=Monday, 7=Sunday)
- Remove calorie_target (nutrition is non-goal)

Approval flow redesign:
- Email link → confirmation page (GET), not auto-approve
- Actual vote is POST from confirmation page
- Per-voter tokens (single-use, 72h TTL)
- Record which member voted

Auth model:
- VPN-only for admin endpoints
- Session-based for family web UI

Docker hardening:
- Remove direct port exposure for backend/frontend
- nginx is sole entrypoint
- Add docker-compose.dev.yml for local dev

Skeleton fixes:
- Add missing Pantry.tsx page
- Add missing index.html (Vite entrypoint)
- Add package-lock.json
- Fix SQLAlchemy 2 text() for raw SQL
- Remove create_all from startup (use migrations)
- Configure Alembic properly

Docs updates:
- Update Lucky URL to luckysupermarkets.com
- Add WCAG 2.1 AA accessibility target
- Update family profile with correct mushroom preferences
- Add external dependencies list to SPEC

Verification:
- docker compose config: PASS
- docker compose build backend: PASS
- docker compose build frontend: PASS
- backend import: PASS
- alembic context: PASS

backend/alembic/env.py

@@ -0,0 +1,55 @@
+from logging.config import fileConfig
+from sqlalchemy import engine_from_config, pool
+from alembic import context
+import sys
+import os
+
+sys.path.insert(0, os.path.dirname(os.path.dirname(__file__)))
+
+from app.models import Base
+from app.config import settings
+
+config = context.config
+
+if config.config_file_name is not None:
+    fileConfig(config.config_file_name)
+
+target_metadata = Base.metadata
+
+config.set_main_option("sqlalchemy.url", settings.DATABASE_URL.replace("postgresql://", "postgresql+psycopg2://"))
+
+
+def run_migrations_offline() -> None:
+    url = config.get_main_option("sqlalchemy.url")
+    context.configure(
+        url=url,
+        target_metadata=target_metadata,
+        literal_binds=True,
+        dialect_opts={"paramstyle": "named"},
+    )
+
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+def run_migrations_online() -> None:
+    connectable = engine_from_config(
+        config.get_section(config.config_ini_section, {}),
+        prefix="sqlalchemy.",
+        poolclass=pool.NullPool,
+    )
+
+    with connectable.connect() as connection:
+        context.configure(
+            connection=connection,
+            target_metadata=target_metadata
+        )
+
+        with context.begin_transaction():
+            context.run_migrations()
+
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    run_migrations_online()