chore: initial commit - consolidate 4 projects into monorepo

Projects included:
- maerchenzauber (NestJS backend + Expo mobile + SvelteKit web + Astro landing)
- manacore (Expo mobile + SvelteKit web + Astro landing)
- manadeck (NestJS backend + Expo mobile + SvelteKit web)
- memoro (Expo mobile + SvelteKit web + Astro landing)

This commit preserves the current state before monorepo restructuring.

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

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

manadeck/apps/mobile/Docs/samples/create-system-user.sql

@@ -0,0 +1,65 @@
+-- Create System User for Sample Decks
+-- This script creates a system user that can be used for sample/public decks
+
+-- Insert system user into auth.users table
+INSERT INTO auth.users (
+    id,
+    aud,
+    role,
+    email,
+    encrypted_password,
+    email_confirmed_at,
+    raw_app_meta_data,
+    raw_user_meta_data,
+    created_at,
+    updated_at,
+    confirmation_token,
+    email_change,
+    email_change_token_new,
+    recovery_token
+) VALUES (
+    '00000000-0000-0000-0000-000000000001',
+    'authenticated',
+    'authenticated',
+    'system@manadeck.app',
+    '$2a$10$dummyhashforpassword',  -- Dummy encrypted password
+    now(),
+    '{"provider": "system", "providers": ["system"]}',
+    '{"display_name": "Manadeck System", "is_system_user": true}',
+    now(),
+    now(),
+    '',
+    '',
+    '',
+    ''
+) ON CONFLICT (id) DO NOTHING;  -- Don't fail if user already exists
+
+-- Create corresponding profile for the system user
+INSERT INTO public.profiles (
+    id,
+    username,
+    display_name,
+    bio,
+    preferences,
+    created_at,
+    updated_at
+) VALUES (
+    '00000000-0000-0000-0000-000000000001',
+    'manadeck_system',
+    'Manadeck System',
+    'System account for managing public sample decks and community content.',
+    '{"is_system_account": true, "can_create_public_decks": true}',
+    now(),
+    now()
+) ON CONFLICT (id) DO NOTHING;
+
+-- Verify the system user was created
+SELECT 
+    u.id,
+    u.email,
+    u.email_confirmed_at IS NOT NULL as email_confirmed,
+    p.username,
+    p.display_name
+FROM auth.users u
+LEFT JOIN public.profiles p ON u.id = p.id
+WHERE u.id = '00000000-0000-0000-0000-000000000001';