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/test/java/com/recipeapp/planning/WeekPlanControllerTest.java

@@ -19,7 +19,6 @@ import org.springframework.test.web.servlet.setup.MockMvcBuilders;
 import java.time.Instant;
 import java.time.LocalDate;
 import java.util.List;
-import java.util.Map;
 import java.util.UUID;
 
 import static org.mockito.ArgumentMatchers.*;
@@ -154,12 +153,12 @@ class WeekPlanControllerTest {
     @Test
     void getSuggestionsShouldReturn200() throws Exception {
         var recipe = new SlotResponse.SlotRecipe(UUID.randomUUID(), "Stir Fry", "easy", (short) 15, null);
-        var item = new SuggestionResponse.SuggestionItem(recipe,
-                List.of("not_cooked_recently"), List.of());
+        var item = new SuggestionResponse.SuggestionItem(recipe, 9.5);
         var response = new SuggestionResponse(List.of(item));
 
         when(householdResolver.resolve("sarah@example.com")).thenReturn(HOUSEHOLD_ID);
-        when(planningService.getSuggestions(HOUSEHOLD_ID, PLAN_ID, WEEK_START.plusDays(2)))
+        when(planningService.getSuggestions(HOUSEHOLD_ID, PLAN_ID, WEEK_START.plusDays(2),
+                List.of(), null))
                 .thenReturn(response);
 
         mockMvc.perform(get("/v1/week-plans/{id}/suggestions", PLAN_ID)
@@ -167,13 +166,13 @@ class WeekPlanControllerTest {
                         .param("slotDate", "2026-04-08"))
                 .andExpect(status().isOk())
                 .andExpect(jsonPath("$.suggestions[0].recipe.name").value("Stir Fry"))
-                .andExpect(jsonPath("$.suggestions[0].fitReasons[0]").value("not_cooked_recently"));
+                .andExpect(jsonPath("$.suggestions[0].simulatedScore").value(9.5));
     }
 
     @Test
     void getVarietyScoreShouldReturn200() throws Exception {
         var response = new VarietyScoreResponse(7.5, List.of(), List.of(),
-                Map.of("easy", 2, "medium", 3, "hard", 2));
+                List.of(), List.of());
 
         when(householdResolver.resolve("sarah@example.com")).thenReturn(HOUSEHOLD_ID);
         when(planningService.getVarietyScore(HOUSEHOLD_ID, PLAN_ID)).thenReturn(response);