feat(backend): recipe enrichment with side dishes & detailed instructions

- Add SideDish/SideDishIngredient schemas and recipe.side_dishes JSONB column
- Add recipe_enrichment.py service using Ollama LLM to:
  - Rewrite vague instructions with specific temps, quantities, timing, sauce breakdowns
  - Suggest 1-2 complementary side dishes with ingredients & prep notes
- Wire enrichment into recipe_ingestion.py discovery pipeline
- Add admin trigger endpoint /api/recipes/{id}/enrich for on-demand enrichment
- Migration 0014: Add side_dishes JSONB to recipe table
- Fix schemas/__init__.py imports: restore RecipeBase/Create/Read exports, add datetime/date for PydanticOptional compatibility
- Deployed to docker-willester and migrated to alembic 0014

backend/alembic/versions/0014_recipe_side_dishes.py

@@ -0,0 +1,28 @@
+"""Add side_dishes JSONB to recipe.
+
+Revision ID: 0014
+Revises: 0013
+Create Date: 2026-05-27
+"""
+from typing import Sequence, Union
+
+import sqlalchemy as sa
+from alembic import op
+from sqlalchemy.dialects import postgresql
+
+# revision identifiers, used by Alembic.
+revision: str = "0014"
+down_revision: Union[str, None] = "0013"
+branch_labels: Union[Sequence[str], None] = None
+depends_on: Union[Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.add_column(
+        "recipe",
+        sa.Column("side_dishes", postgresql.JSONB, nullable=True),
+    )
+
+
+def downgrade() -> None:
+    op.drop_column("recipe", "side_dishes")