feat(chat): integrate chat project into monorepo with full app structure

- Restructure chat as apps/mobile, apps/web, apps/landing, backend
- Add NestJS backend for secure Azure OpenAI API calls
- Remove exposed API key from mobile app (security fix)
- Add shared chat-types package
- Create SvelteKit web app scaffold
- Create Astro landing page scaffold
- Update pnpm workspace configuration
- Add project-level CLAUDE.md documentation

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

chat/apps/mobile/scripts/create_users_table.sql

@@ -0,0 +1,103 @@
+-- Erstelle oder aktualisiere die users-Tabelle im public-Schema
+
+-- Prüfe, ob die users-Tabelle bereits existiert
+DO $$
+BEGIN
+  IF NOT EXISTS (
+    SELECT FROM information_schema.tables 
+    WHERE table_schema = 'public' 
+    AND table_name = 'users'
+  ) THEN
+    -- Erstelle die users-Tabelle
+    CREATE TABLE public.users (
+      id UUID PRIMARY KEY,
+      email TEXT UNIQUE NOT NULL,
+      name TEXT,
+      created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
+      updated_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
+    );
+    
+    -- Erstelle einen Trigger für updated_at
+    CREATE OR REPLACE FUNCTION set_updated_at()
+    RETURNS TRIGGER AS $func$
+    BEGIN
+      NEW.updated_at = NOW();
+      RETURN NEW;
+    END;
+    $func$ LANGUAGE plpgsql;
+    
+    CREATE TRIGGER set_users_updated_at
+    BEFORE UPDATE ON public.users
+    FOR EACH ROW
+    EXECUTE FUNCTION set_updated_at();
+    
+    RAISE NOTICE 'Tabelle users wurde erstellt.';
+  ELSE
+    RAISE NOTICE 'Tabelle users existiert bereits.';
+  END IF;
+END
+$$;
+
+-- Erstelle eine Funktion, um Benutzer aus auth.users in public.users zu synchronisieren
+CREATE OR REPLACE FUNCTION sync_user_after_auth_event()
+RETURNS TRIGGER AS $sync_func$
+BEGIN
+  IF (TG_OP = 'INSERT' OR TG_OP = 'UPDATE') AND NEW.confirmed_at IS NOT NULL THEN
+    -- Füge den Benutzer in die public.users-Tabelle ein oder aktualisiere ihn
+    INSERT INTO public.users (id, email, name, created_at, updated_at)
+    VALUES (
+      NEW.id,
+      NEW.email,
+      COALESCE(NEW.raw_user_meta_data->>'name', NEW.email),
+      NEW.created_at,
+      NEW.updated_at
+    )
+    ON CONFLICT (id) DO UPDATE SET
+      email = EXCLUDED.email,
+      name = COALESCE(NEW.raw_user_meta_data->>'name', NEW.email),
+      updated_at = NOW();
+  END IF;
+  RETURN NEW;
+END;
+$sync_func$ LANGUAGE plpgsql SECURITY DEFINER;
+
+-- Erstelle einen Trigger für die auth.users-Tabelle
+DROP TRIGGER IF EXISTS sync_user_after_auth_event_trigger ON auth.users;
+CREATE TRIGGER sync_user_after_auth_event_trigger
+AFTER INSERT OR UPDATE ON auth.users
+FOR EACH ROW
+EXECUTE FUNCTION sync_user_after_auth_event();
+
+-- Synchronisiere bestehende Benutzer
+INSERT INTO public.users (id, email, name, created_at, updated_at)
+SELECT 
+  id,
+  email,
+  COALESCE(raw_user_meta_data->>'name', email) as name,
+  created_at,
+  updated_at
+FROM auth.users
+WHERE confirmed_at IS NOT NULL
+ON CONFLICT (id) DO UPDATE SET
+  email = EXCLUDED.email,
+  name = COALESCE(EXCLUDED.name, users.name),
+  updated_at = NOW();
+
+-- Aktiviere RLS für die users-Tabelle
+ALTER TABLE public.users ENABLE ROW LEVEL SECURITY;
+
+-- Erstelle eine Richtlinie für das Lesen von Benutzern
+-- Benutzer dürfen nur ihre eigenen Daten sehen
+CREATE POLICY users_select_policy
+ON public.users
+FOR SELECT
+TO authenticated
+USING (id = auth.uid());
+
+-- Erstelle eine Richtlinie für das Aktualisieren von Benutzern
+-- Benutzer dürfen nur ihre eigenen Daten aktualisieren
+CREATE POLICY users_update_policy
+ON public.users
+FOR UPDATE
+TO authenticated
+USING (id = auth.uid());