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/check_and_create_models.sql

@@ -0,0 +1,84 @@
+-- Überprüfe und erstelle Modelle in der Datenbank
+
+-- 1. Überprüfe, ob die models-Tabelle existiert
+DO $$
+BEGIN
+  IF NOT EXISTS (
+    SELECT FROM information_schema.tables 
+    WHERE table_schema = 'public' 
+    AND table_name = 'models'
+  ) THEN
+    -- Erstelle die models-Tabelle
+    CREATE TABLE public.models (
+      id UUID PRIMARY KEY,
+      name TEXT NOT NULL,
+      description TEXT,
+      parameters JSONB,
+      created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
+      updated_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
+    );
+    
+    -- Erstelle einen Trigger für updated_at
+    CREATE OR REPLACE FUNCTION set_updated_at()
+    RETURNS TRIGGER AS $func$
+    BEGIN
+      NEW.updated_at = NOW();
+      RETURN NEW;
+    END;
+    $func$ LANGUAGE plpgsql;
+    
+    CREATE TRIGGER set_models_updated_at
+    BEFORE UPDATE ON public.models
+    FOR EACH ROW
+    EXECUTE FUNCTION set_updated_at();
+    
+    RAISE NOTICE 'Tabelle models wurde erstellt.';
+  ELSE
+    RAISE NOTICE 'Tabelle models existiert bereits.';
+  END IF;
+END
+$$;
+
+-- 2. Überprüfe die Struktur der models-Tabelle und füge updated_at hinzu, falls es fehlt
+DO $$
+BEGIN
+  IF NOT EXISTS (
+    SELECT FROM information_schema.columns 
+    WHERE table_schema = 'public' 
+    AND table_name = 'models' 
+    AND column_name = 'updated_at'
+  ) THEN
+    ALTER TABLE public.models ADD COLUMN updated_at TIMESTAMP WITH TIME ZONE DEFAULT NOW();
+    RAISE NOTICE 'Spalte updated_at zur models-Tabelle hinzugefügt.';
+  ELSE
+    RAISE NOTICE 'Spalte updated_at existiert bereits in der models-Tabelle.';
+  END IF;
+END
+$$;
+
+-- 3. Füge Standard-Modelle ein
+INSERT INTO public.models (id, name, description, parameters)
+VALUES
+  ('550e8400-e29b-41d4-a716-446655440000', 'GPT-O3-Mini', 'Azure OpenAI GPT-O3-Mini', '{"temperature": 0.7, "max_tokens": 800}'),
+  ('550e8400-e29b-41d4-a716-446655440001', 'GPT-4', 'OpenAI GPT-4', '{"temperature": 0.7, "max_tokens": 1000}'),
+  ('550e8400-e29b-41d4-a716-446655440002', 'GPT-3.5-Turbo', 'OpenAI GPT-3.5 Turbo', '{"temperature": 0.7, "max_tokens": 800}'),
+  ('550e8400-e29b-41d4-a716-446655440003', 'Claude 3', 'Anthropic Claude 3', '{"temperature": 0.7, "max_tokens": 1000}')
+ON CONFLICT (id) DO UPDATE SET
+  name = EXCLUDED.name,
+  description = EXCLUDED.description,
+  parameters = EXCLUDED.parameters;
+
+-- 4. Aktiviere RLS für die models-Tabelle
+ALTER TABLE public.models ENABLE ROW LEVEL SECURITY;
+
+-- 5. Erstelle eine Richtlinie für das Lesen von Modellen
+-- Alle authentifizierten Benutzer dürfen Modelle sehen
+DROP POLICY IF EXISTS models_select_policy ON models;
+CREATE POLICY models_select_policy
+ON models
+FOR SELECT
+TO authenticated
+USING (true);
+
+-- 6. Überprüfe, ob die Modelle existieren
+SELECT id, name, description FROM public.models;