feat(wishlist): per-user Wünsche + Header-Badge mit Gesamtzahl

Schema-Änderung (Migration 005):
- Tabelle wishlist umgestellt auf PK (recipe_id, profile_id)
- wishlist_like-Tabelle zusammengelegt — Liken WAR schon "will ich auch",
  also werden alle bestehenden Likes Memberships auf der neuen Tabelle.
- Alt-Einträge mit added_by_profile_id werden migriert, anonyme gehen
  verloren (war inkonsistent, jetzt erzwingen wir profile_id NOT NULL).

Repository:
- listWishlist aggregiert pro Rezept: wanted_by_count, wanted_by_names
  (kommagetrennt), on_my_wishlist für das aktive Profil
- listWishlistProfileIds(recipeId) für den Recipe-Page-Loader
- countWishlistRecipes für das Header-Badge (DISTINCT recipe_id)
- addToWishlist/removeFromWishlist/isOnMyWishlist alle mit profile_id
  als Pflicht

API:
- POST /api/wishlist: profile_id jetzt Pflicht (nullable raus)
- DELETE /api/wishlist/[recipe_id]?profile_id=X (nur eigenes Entry)
- /api/wishlist/[recipe_id]/like komplett entfernt (Konzept obsolet)
- Neu: GET /api/wishlist/count → { count: <distinct recipes> }

UI:
- Header-Heart bekommt rotes Badge mit Zahl der Wunschliste-Rezepte.
  wishlistStore in $lib/client/wishlist.svelte.ts hält den Count reaktiv;
  Refresh auf Mount, nach Add/Remove, beim Öffnen der Wunschliste.
- Recipe-Detail: Loader liefert wishlist_profile_ids; onMyWishlist ist
  ein $derived. Toggle fragt aktives Profil (alertAction sonst), mutiert
  die lokale Liste + ruft wishlistStore.refresh.
- Wunschliste-Seite: Heart toggelt eigenen Wunsch, Count zeigt Gesamt-
  wünsche, kommagetrennte Namen zeigen "wer will". Trash-Button
  entfernt — Heart-off reicht jetzt.

Tests (99 → 99, 8 neu geschrieben):
- Per-User-Add/Remove, aggregierte Counts, on_my_wishlist, Cascades bei
  Recipe/Profile-Delete, countWishlistRecipes = DISTINCT.

tests/integration/wishlist.test.ts

@@ -7,9 +7,9 @@ import {
   addToWishlist,
   removeFromWishlist,
   listWishlist,
-  isOnWishlist,
-  likeWish,
-  unlikeWish
+  listWishlistProfileIds,
+  isOnMyWishlist,
+  countWishlistRecipes
 } from '../../src/lib/server/wishlist/repository';
 import type { Recipe } from '../../src/lib/types';
 
@@ -38,96 +38,95 @@ beforeEach(() => {
   db = openInMemoryForTest();
 });
 
-describe('wishlist add/remove', () => {
-  it('adds and lists', () => {
+describe('per-user wishlist', () => {
+  it('adds and lists for a single profile', () => {
     const r1 = insertRecipe(db, recipe('Carbonara'));
     const p = createProfile(db, 'Hendrik');
     addToWishlist(db, r1, p.id);
-    expect(isOnWishlist(db, r1)).toBe(true);
+    expect(isOnMyWishlist(db, r1, p.id)).toBe(true);
+
     const list = listWishlist(db, p.id);
     expect(list.length).toBe(1);
     expect(list[0].title).toBe('Carbonara');
-    expect(list[0].added_by_name).toBe('Hendrik');
+    expect(list[0].wanted_by_count).toBe(1);
+    expect(list[0].wanted_by_names).toBe('Hendrik');
+    expect(list[0].on_my_wishlist).toBe(1);
   });
 
-  it('is idempotent on double-add', () => {
+  it('aggregates multiple users per recipe', () => {
+    const r1 = insertRecipe(db, recipe('Pizza'));
+    const a = createProfile(db, 'Alice');
+    const b = createProfile(db, 'Bob');
+    const c = createProfile(db, 'Cara');
+    addToWishlist(db, r1, a.id);
+    addToWishlist(db, r1, b.id);
+    addToWishlist(db, r1, c.id);
+
+    const listFromA = listWishlist(db, a.id);
+    expect(listFromA.length).toBe(1);
+    expect(listFromA[0].wanted_by_count).toBe(3);
+    expect(listFromA[0].on_my_wishlist).toBe(1);
+
+    const ids = listWishlistProfileIds(db, r1);
+    expect(ids.sort()).toEqual([a.id, b.id, c.id].sort());
+  });
+
+  it('is idempotent on double-add for same profile', () => {
     const r1 = insertRecipe(db, recipe('Pizza'));
     const p = createProfile(db, 'A');
     addToWishlist(db, r1, p.id);
     addToWishlist(db, r1, p.id);
-    expect(listWishlist(db, p.id).length).toBe(1);
+    const list = listWishlist(db, p.id);
+    expect(list[0].wanted_by_count).toBe(1);
   });
 
-  it('removes', () => {
-    const r1 = insertRecipe(db, recipe('X'));
-    addToWishlist(db, r1, null);
-    removeFromWishlist(db, r1);
-    expect(listWishlist(db, null).length).toBe(0);
+  it('removes only my entry, keeps others', () => {
+    const r1 = insertRecipe(db, recipe('Salad'));
+    const a = createProfile(db, 'A');
+    const b = createProfile(db, 'B');
+    addToWishlist(db, r1, a.id);
+    addToWishlist(db, r1, b.id);
+    removeFromWishlist(db, r1, a.id);
+    expect(isOnMyWishlist(db, r1, a.id)).toBe(false);
+    expect(isOnMyWishlist(db, r1, b.id)).toBe(true);
+    expect(listWishlist(db, b.id)[0].wanted_by_count).toBe(1);
   });
 
-  it('cascades with recipe delete', () => {
+  it('on_my_wishlist is 0 for profiles that did not wish', () => {
+    const r1 = insertRecipe(db, recipe('Curry'));
+    const a = createProfile(db, 'A');
+    const b = createProfile(db, 'B');
+    addToWishlist(db, r1, a.id);
+
+    const listFromB = listWishlist(db, b.id);
+    expect(listFromB[0].on_my_wishlist).toBe(0);
+    expect(listFromB[0].wanted_by_count).toBe(1);
+  });
+
+  it('cascades when recipe is deleted', () => {
     const r1 = insertRecipe(db, recipe('X'));
-    addToWishlist(db, r1, null);
+    const a = createProfile(db, 'A');
+    addToWishlist(db, r1, a.id);
     db.prepare('DELETE FROM recipe WHERE id = ?').run(r1);
+    expect(listWishlist(db, a.id).length).toBe(0);
+  });
+
+  it('cascades when profile is deleted', () => {
+    const r1 = insertRecipe(db, recipe('X'));
+    const a = createProfile(db, 'A');
+    addToWishlist(db, r1, a.id);
+    db.prepare('DELETE FROM profile WHERE id = ?').run(a.id);
     expect(listWishlist(db, null).length).toBe(0);
   });
-});
 
-describe('wishlist likes + sort', () => {
-  it('counts likes per entry and shows liked_by_me for active profile', () => {
+  it('countWishlistRecipes counts distinct recipes (not rows)', () => {
     const r1 = insertRecipe(db, recipe('R1'));
     const r2 = insertRecipe(db, recipe('R2'));
     const a = createProfile(db, 'A');
     const b = createProfile(db, 'B');
-    const c = createProfile(db, 'C');
     addToWishlist(db, r1, a.id);
+    addToWishlist(db, r1, b.id); // same recipe, different user
     addToWishlist(db, r2, a.id);
-    likeWish(db, r1, a.id);
-    likeWish(db, r1, b.id);
-    likeWish(db, r1, c.id);
-    likeWish(db, r2, a.id);
-
-    const listA = listWishlist(db, a.id, 'popular');
-    expect(listA[0].title).toBe('R1');
-    expect(listA[0].like_count).toBe(3);
-    expect(listA[0].liked_by_me).toBe(1);
-    expect(listA[1].title).toBe('R2');
-    expect(listA[1].like_count).toBe(1);
-
-    const listB = listWishlist(db, b.id);
-    expect(listB.find((e) => e.recipe_id === r1)!.liked_by_me).toBe(1);
-    expect(listB.find((e) => e.recipe_id === r2)!.liked_by_me).toBe(0);
-  });
-
-  it('unlike is idempotent and decrements count', () => {
-    const r = insertRecipe(db, recipe('R'));
-    const a = createProfile(db, 'A');
-    addToWishlist(db, r, a.id);
-    likeWish(db, r, a.id);
-    unlikeWish(db, r, a.id);
-    unlikeWish(db, r, a.id);
-    const [entry] = listWishlist(db, a.id);
-    expect(entry.like_count).toBe(0);
-    expect(entry.liked_by_me).toBe(0);
-  });
-
-  it('sort=newest orders by added_at desc, oldest asc', () => {
-    const r1 = insertRecipe(db, recipe('First'));
-    // Force different timestamps via raw insert with explicit added_at
-    db.prepare("INSERT INTO wishlist(recipe_id, added_at) VALUES (?, '2026-01-01 10:00:00')").run(r1);
-    const r2 = insertRecipe(db, recipe('Second'));
-    db.prepare("INSERT INTO wishlist(recipe_id, added_at) VALUES (?, '2026-01-02 10:00:00')").run(r2);
-
-    expect(listWishlist(db, null, 'newest').map((e) => e.title)).toEqual(['Second', 'First']);
-    expect(listWishlist(db, null, 'oldest').map((e) => e.title)).toEqual(['First', 'Second']);
-  });
-
-  it('handles anonymous (no active profile) — liked_by_me always 0', () => {
-    const r = insertRecipe(db, recipe('R'));
-    addToWishlist(db, r, null);
-    likeWish(db, r, createProfile(db, 'A').id);
-    const [entry] = listWishlist(db, null);
-    expect(entry.like_count).toBe(1);
-    expect(entry.liked_by_me).toBe(0);
+    expect(countWishlistRecipes(db)).toBe(2);
   });
 });