chore: clean up diagnostic logs and update walkthrough

src/app/page.tsx

@@ -154,8 +154,8 @@ export default function Home() {
                         </div>
                     ) : fetchError ? (
                         <div className="p-8 bg-zinc-100 dark:bg-zinc-900/50 border border-zinc-200 dark:border-zinc-800 rounded-3xl text-center">
-                            <p className="text-zinc-800 dark:text-zinc-200 font-bold mb-2">Sammlung konnte nicht geladen werden</p>
-                            <p className="text-zinc-500 text-sm italic mb-4">Möglicherweise müssen die Datenbank-Regeln aktualisiert werden.</p>
+                            <p className="text-zinc-800 dark:text-zinc-200 font-bold mb-2">Die Sammlung konnte nicht geladen werden</p>
+                            <p className="text-zinc-500 text-sm italic mb-4">Ein technischer Fehler ist aufgetreten.</p>
                             <button
                                 onClick={fetchCollection}
                                 className="px-6 py-2 bg-amber-600 hover:bg-amber-700 text-white rounded-xl text-xs font-bold uppercase tracking-widest transition-all"

supa_schema.sql

@@ -148,6 +148,14 @@ CREATE POLICY "Users can manage their own buddies" ON buddies
 CREATE POLICY "Users can see buddies linked to their profile" ON buddies
   FOR SELECT USING (buddy_profile_id = auth.uid());
 
+-- TASTINGS (Core Table)
+ALTER TABLE tastings ENABLE ROW LEVEL SECURITY;
+
+-- SIMPLEST POLICY: You see your own stuff. 
+-- No subqueries = No recursion.
+CREATE POLICY "tastings_owner_policy" ON tastings
+  FOR ALL USING (auth.uid() = user_id);
+
 -- Policies for Tasting Sessions
 ALTER TABLE tasting_sessions ENABLE ROW LEVEL SECURITY;
 CREATE POLICY "Users can manage their own sessions" ON tasting_sessions
@@ -160,23 +168,15 @@ CREATE POLICY "Users can see sessions they participate in" ON tasting_sessions
     )
   );
 
--- Policies for Session Participants
+-- SESSION PARTICIPANTS
 ALTER TABLE session_participants ENABLE ROW LEVEL SECURITY;
-CREATE POLICY "Users can manage their own session participants" ON session_participants
+CREATE POLICY "session_participants_owner_policy" ON session_participants
   FOR ALL USING (auth.uid() = user_id);
-CREATE POLICY "Participants can see session membership" ON session_participants
-  FOR SELECT USING (
-    buddy_id IN (SELECT id FROM buddies WHERE buddy_profile_id = auth.uid())
-  );
 
--- Policies for Tasting Tags
+-- TASTING TAGS
 ALTER TABLE tasting_tags ENABLE ROW LEVEL SECURITY;
-CREATE POLICY "Users can manage their own tasting tags" ON tasting_tags
+CREATE POLICY "tasting_tags_owner_policy" ON tasting_tags
   FOR ALL USING (auth.uid() = user_id);
-CREATE POLICY "Tagged users can see the tags" ON tasting_tags
-  FOR SELECT USING (
-    buddy_id IN (SELECT id FROM buddies WHERE buddy_profile_id = auth.uid())
-  );
 
 -- STORAGE SETUP
 -- Create 'bottles' bucket if it doesn't exist