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.

src/lib/server/db/migrations/005_wishlist_per_user.sql

@@ -0,0 +1,29 @@
+-- Wishlist: from "one entry per recipe" to "per-user membership".
+-- Multiple profiles can now wish for the same recipe. The old wishlist_like
+-- table merges into this — liking WAS already "me too", so existing likes
+-- become wishlist memberships.
+
+CREATE TABLE wishlist_new (
+  recipe_id  INTEGER NOT NULL REFERENCES recipe(id) ON DELETE CASCADE,
+  profile_id INTEGER NOT NULL REFERENCES profile(id) ON DELETE CASCADE,
+  added_at   TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  PRIMARY KEY (recipe_id, profile_id)
+);
+
+-- Preserve existing explicit additions (only if a profile was attached)
+INSERT OR IGNORE INTO wishlist_new (recipe_id, profile_id, added_at)
+  SELECT recipe_id, added_by_profile_id, added_at
+  FROM wishlist
+  WHERE added_by_profile_id IS NOT NULL;
+
+-- Likes become memberships
+INSERT OR IGNORE INTO wishlist_new (recipe_id, profile_id, added_at)
+  SELECT recipe_id, profile_id, created_at
+  FROM wishlist_like;
+
+DROP TABLE wishlist_like;
+DROP TABLE wishlist;
+ALTER TABLE wishlist_new RENAME TO wishlist;
+
+CREATE INDEX idx_wishlist_profile ON wishlist(profile_id);
+CREATE INDEX idx_wishlist_recipe  ON wishlist(recipe_id);

src/lib/server/wishlist/repository.ts

@@ -5,11 +5,10 @@ export type WishlistEntry = {
   title: string;
   image_path: string | null;
   source_domain: string | null;
-  added_by_profile_id: number | null;
-  added_by_name: string | null;
-  added_at: string;
-  like_count: number;
-  liked_by_me: 0 | 1;
+  added_at: string; // earliest per recipe
+  wanted_by_count: number;
+  wanted_by_names: string;  // comma-joined profile names
+  on_my_wishlist: 0 | 1;
   avg_stars: number | null;
 };
 
@@ -21,9 +20,9 @@ export function listWishlist(
   sort: SortKey = 'popular'
 ): WishlistEntry[] {
   const orderBy = {
-    popular: 'like_count DESC, w.added_at DESC',
-    newest: 'w.added_at DESC',
-    oldest: 'w.added_at ASC'
+    popular: 'wanted_by_count DESC, first_added DESC',
+    newest: 'first_added DESC',
+    oldest: 'first_added ASC'
   }[sort];
 
   return db
@@ -33,66 +32,76 @@ export function listWishlist(
          r.title,
          r.image_path,
          r.source_domain,
-         w.added_by_profile_id,
-         p.name AS added_by_name,
-         w.added_at,
-         (SELECT COUNT(*) FROM wishlist_like wl WHERE wl.recipe_id = w.recipe_id) AS like_count,
+         MIN(w.added_at) AS first_added,
+         MIN(w.added_at) AS added_at,
+         COUNT(w.profile_id) AS wanted_by_count,
+         COALESCE(GROUP_CONCAT(p.name, ', '), '') AS wanted_by_names,
          CASE
            WHEN ? IS NULL THEN 0
-           WHEN EXISTS (SELECT 1 FROM wishlist_like wl
-                         WHERE wl.recipe_id = w.recipe_id AND wl.profile_id = ?)
+           WHEN EXISTS (SELECT 1 FROM wishlist w2
+                         WHERE w2.recipe_id = w.recipe_id AND w2.profile_id = ?)
              THEN 1
            ELSE 0
-         END AS liked_by_me,
+         END AS on_my_wishlist,
          (SELECT AVG(stars) FROM rating WHERE recipe_id = w.recipe_id) AS avg_stars
        FROM wishlist w
        JOIN recipe r ON r.id = w.recipe_id
-       LEFT JOIN profile p ON p.id = w.added_by_profile_id
+       LEFT JOIN profile p ON p.id = w.profile_id
+       GROUP BY w.recipe_id
        ORDER BY ${orderBy}`
     )
     .all(activeProfileId, activeProfileId) as WishlistEntry[];
 }
 
-export function isOnWishlist(db: Database.Database, recipeId: number): boolean {
+export function listWishlistProfileIds(
+  db: Database.Database,
+  recipeId: number
+): number[] {
   return (
     db
-      .prepare('SELECT 1 AS ok FROM wishlist WHERE recipe_id = ?')
-      .get(recipeId) !== undefined
-  );
+      .prepare('SELECT profile_id FROM wishlist WHERE recipe_id = ?')
+      .all(recipeId) as { profile_id: number }[]
+  ).map((r) => r.profile_id);
+}
+
+export function countWishlistRecipes(db: Database.Database): number {
+  const row = db
+    .prepare('SELECT COUNT(DISTINCT recipe_id) AS n FROM wishlist')
+    .get() as { n: number };
+  return row.n;
 }
 
 export function addToWishlist(
   db: Database.Database,
   recipeId: number,
-  profileId: number | null
+  profileId: number
 ): void {
   db.prepare(
-    `INSERT INTO wishlist(recipe_id, added_by_profile_id)
+    `INSERT INTO wishlist(recipe_id, profile_id)
      VALUES (?, ?)
-     ON CONFLICT(recipe_id) DO NOTHING`
+     ON CONFLICT(recipe_id, profile_id) DO NOTHING`
   ).run(recipeId, profileId);
 }
 
-export function removeFromWishlist(db: Database.Database, recipeId: number): void {
-  db.prepare('DELETE FROM wishlist WHERE recipe_id = ?').run(recipeId);
-}
-
-export function likeWish(
+export function removeFromWishlist(
   db: Database.Database,
   recipeId: number,
   profileId: number
 ): void {
-  db.prepare(
-    'INSERT OR IGNORE INTO wishlist_like(recipe_id, profile_id) VALUES (?, ?)'
-  ).run(recipeId, profileId);
+  db.prepare('DELETE FROM wishlist WHERE recipe_id = ? AND profile_id = ?').run(
+    recipeId,
+    profileId
+  );
 }
 
-export function unlikeWish(
+export function isOnMyWishlist(
   db: Database.Database,
   recipeId: number,
   profileId: number
-): void {
-  db.prepare(
-    'DELETE FROM wishlist_like WHERE recipe_id = ? AND profile_id = ?'
-  ).run(recipeId, profileId);
+): boolean {
+  return (
+    db
+      .prepare('SELECT 1 AS ok FROM wishlist WHERE recipe_id = ? AND profile_id = ?')
+      .get(recipeId, profileId) !== undefined
+  );
 }