Rewrite variety score and suggestions with configurable scoring

- Add VarietyScoreConfig entity, repository, and V020 migration for
  per-household scoring weights and configurable tag types
- Rewrite getVarietyScore: tag-type repeats on consecutive days,
  non-staple ingredient overlaps, cooking log history, plan duplicates
- Rewrite getSuggestions: simulate variety score for each candidate,
  add tag filter (AND, case-insensitive) and configurable topN param
- Update SuggestionResponse to return simulatedScore instead of
  fitReasons/warnings, update VarietyScoreResponse to new shape
- Seed default VarietyScoreConfig on household creation
- Extend test suite across all domains (+270 tests, all passing)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/src/main/java/com/recipeapp/planning/WeekPlanController.java

@@ -9,6 +9,7 @@ import org.springframework.web.bind.annotation.*;
 
 import java.security.Principal;
 import java.time.LocalDate;
+import java.util.List;
 import java.util.UUID;
 
 @RestController
@@ -78,9 +79,12 @@ public class WeekPlanController {
     public SuggestionResponse getSuggestions(
             Principal principal,
             @PathVariable UUID id,
-            @RequestParam LocalDate slotDate) {
+            @RequestParam LocalDate slotDate,
+            @RequestParam(required = false) List<String> tags,
+            @RequestParam(required = false) Integer topN) {
         UUID householdId = householdResolver.resolve(principal.getName());
-        return planningService.getSuggestions(householdId, id, slotDate);
+        return planningService.getSuggestions(householdId, id, slotDate,
+                tags != null ? tags : List.of(), topN);
     }
 
     @GetMapping("/{id}/variety-score")