feat(backend): tunable planner weights via family profile config

- Add planner_config JSONB to family_profile model + migration
- Add PlannerConfig.merge(overrides) + to_dict() for family-level override merging
- generate_meal_plan merges family.planner_config into DEFAULT before filtering/scoring/selection
- New endpoints on /api/profile:
  - GET /planner-config — returns merged effective config
  - PUT /planner-config — partial override validation + merge
  - DELETE /planner-config — reset to system defaults
- Schemas: PlannerConfigOverride, PlannerConfigResponse, PlannerConfigUpdateRequest
  with weight-sum validation (0.999–1.001)
- Export RecipeBase/Create/Read/Update from schemas/__init__ to resolve forward refs

backend/app/api/profile.py

@@ -6,6 +6,8 @@ from app.schemas import (
     FamilyProfileResponse, FamilyProfileUpdate, FamilyProfileCreate,
     FamilyMemberResponse, FamilyMemberCreate
 )
+from app.schemas.planner_config import PlannerConfigOverride, PlannerConfigResponse, PlannerConfigUpdateRequest
+from app.services.planner.config import DEFAULT
 from app.security import require_session
 from uuid import UUID
 from typing import List
@@ -78,4 +80,69 @@ def delete_member(member_id: UUID, db: Session = Depends(get_db)):
 
     db.delete(member)
     db.commit()
-    return {"message": "Member deleted"}
+    return {"message": "Member deleted"}
+
+
+@router.get("/planner-config", response_model=PlannerConfigResponse)
+def get_planner_config(db: Session = Depends(get_db)):
+    """Return the effective planner configuration for the family (merged defaults + overrides)."""
+    profile = db.query(FamilyProfile).first()
+    if not profile:
+        raise HTTPException(status_code=404, detail="Family profile not found")
+
+    effective = DEFAULT
+    if profile.planner_config:
+        try:
+            effective = DEFAULT.merge(profile.planner_config)
+        except ValueError:
+            pass  # fall back to default
+
+    data = effective.to_dict()
+    data["source"] = "family_override" if profile.planner_config else "default"
+    return data
+
+
+@router.put("/planner-config", response_model=PlannerConfigResponse, dependencies=[Depends(require_session)])
+def update_planner_config(payload: PlannerConfigUpdateRequest, db: Session = Depends(get_db)):
+    """Update the family planner_config.  Partial overrides are merged into defaults."""
+    profile = db.query(FamilyProfile).first()
+    if not profile:
+        raise HTTPException(status_code=404, detail="Family profile not found")
+
+    # Build a clean dict of overrides
+    overrides = payload.planner_config.model_dump(exclude_unset=True, exclude_none=True)
+    if not overrides:
+        raise HTTPException(status_code=400, detail="No overrides provided")
+
+    # Merge with existing family config if present
+    existing = dict(profile.planner_config) if profile.planner_config else {}
+    merged = {**existing, **overrides}
+
+    # Validate via PlannerConfig
+    try:
+        DEFAULT.merge(merged)
+    except Exception as exc:
+        raise HTTPException(status_code=400, detail=f"Invalid planner config: {exc}")
+
+    profile.planner_config = merged
+    db.commit()
+    db.refresh(profile)
+
+    effective = DEFAULT.merge(merged)
+    data = effective.to_dict()
+    data["source"] = "family_override"
+    return data
+
+
+@router.delete("/planner-config", dependencies=[Depends(require_session)])
+def reset_planner_config(db: Session = Depends(get_db)):
+    """Clear family planner_config and restore system defaults."""
+    profile = db.query(FamilyProfile).first()
+    if not profile:
+        raise HTTPException(status_code=404, detail="Family profile not found")
+
+    profile.planner_config = None
+    db.commit()
+    data = DEFAULT.to_dict()
+    data["source"] = "default"
+    return data