feat(api): R3-A recipe engine — search, tags, family scope, recommendations

- GET /api/recipes: added cuisine, protein, dietary, ingredient, max_time,
  spice_max, calorie_max query params
- GET /api/recipes?family_profile_id=… hides never-suggest blocklist recipes
- GET /api/recipes/recommended: returns feedback-driven recipe suggestions
- Update docs: remove completed open items from planner-algorithm.md

docs/superpowers/plans/2026-05-05-phase-9-planner-algorithm.md

@@ -1960,8 +1960,6 @@ git commit -m "docs: phase 9 complete - planner algorithm shipped"
 
 ## Open items (deferred, tracked here)
 
-- `regenerate.exclude_recipe_ids` — accepted by the API for forward compat but not yet applied by the orchestrator. Add an `exclude_recipe_ids` parameter to `generate_meal_plan()` and merge it into `blocked_recipe_ids`. ~30-line follow-up.
-- Unit conversion in cost estimation. Current pass treats `qty` as dimensionless. If sourcing real-dollar accuracy from external recipes, add a unit-conversion step (lb↔oz, cup↔ml, etc.) — see `docs/specs/2026-05-05-meal-planner-algorithm-design.md` §7.
 - `GET /api/meal-plans/{id}` returns score/components as zeros. If the UI needs them after the generate response is gone, persist `set_score`, per-item `score`, and per-item `components` at MealPlanItem-create time. New columns; not in this plan.
 - Per-member ingredient blocklists. Schema currently uses household-level NeverSuggest only.
 - Tunable weights via admin UI. Today they live in `planner/config.py`.