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/theme/ThemeProvider.tsx

@@ -0,0 +1,41 @@
+import React, { createContext, useContext, useState, useEffect } from 'react';
+import { useColorScheme } from 'react-native';
+import { lightTheme, darkTheme } from './index';
+import { Theme } from '@react-navigation/native';
+
+type ThemeContextType = {
+  isDarkMode: boolean;
+  toggleTheme: () => void;
+  theme: Theme;
+};
+
+const ThemeContext = createContext<ThemeContextType>({
+  isDarkMode: false,
+  toggleTheme: () => {},
+  theme: lightTheme,
+});
+
+export const useAppTheme = () => useContext(ThemeContext);
+
+export function ThemeProvider({ children }: { children: React.ReactNode }) {
+  const colorScheme = useColorScheme();
+  const [isDarkMode, setIsDarkMode] = useState(colorScheme === 'dark');
+
+  // Aktualisiere den Theme-Modus, wenn sich das System-Theme ändert
+  useEffect(() => {
+    setIsDarkMode(colorScheme === 'dark');
+  }, [colorScheme]);
+
+  const toggleTheme = () => {
+    setIsDarkMode((prev) => !prev);
+  };
+
+  const theme = isDarkMode ? darkTheme : lightTheme;
+
+  return (
+    <ThemeContext.Provider value={{ isDarkMode, toggleTheme, theme }}>
+      {/* Wir verwenden die NativeWind-Klassen direkt in den Komponenten */}
+      {children}
+    </ThemeContext.Provider>
+  );
+}

chat/apps/mobile/theme/index.ts

@@ -0,0 +1,83 @@
+import { DefaultTheme, DarkTheme } from '@react-navigation/native';
+
+export const lightTheme = {
+  ...DefaultTheme,
+  colors: {
+    ...DefaultTheme.colors,
+    primary: '#0A84FF',
+    secondary: '#5E5CE6',
+    background: '#F2F2F7',
+    card: '#FFFFFF',
+    text: '#000000',
+    border: '#E5E5EA',
+    notification: '#FF3B30',
+    placeholder: '#8E8E93',
+    accent: '#34C759',
+    muted: '#C7C7CC',
+    // Hover-States für Buttons und Menüpunkte
+    buttonHover: 'rgba(255, 255, 255, 0.7)',   // Neutral weiß, heller
+    menuItemHover: 'rgba(255, 255, 255, 0.5)', // Neutral weiß, weniger intensiv
+    cardHover: 'rgba(255, 255, 255, 0.3)',     // Neutral weiß, subtil
+    dangerHover: 'rgba(255, 255, 255, 0.5)',   // Neutral weiß für Danger-Buttons
+  },
+};
+
+export const darkTheme = {
+  ...DarkTheme,
+  colors: {
+    ...DarkTheme.colors,
+    primary: '#0A84FF',
+    secondary: '#5E5CE6',
+    background: '#1C1C1E',
+    card: '#2C2C2E',
+    text: '#FFFFFF',
+    border: '#38383A',
+    notification: '#FF453A',
+    placeholder: '#8E8E93',
+    accent: '#30D158',
+    muted: '#48484A',
+    // Hover-States für Buttons und Menüpunkte
+    buttonHover: 'rgba(255, 255, 255, 0.15)',  // Neutral weiß, heller für Dark Mode
+    menuItemHover: 'rgba(255, 255, 255, 0.1)',  // Neutral weiß, dezent
+    cardHover: 'rgba(255, 255, 255, 0.05)',     // Neutral weiß, sehr dezent
+    dangerHover: 'rgba(255, 255, 255, 0.15)',   // Neutral weiß für Danger-Buttons
+  },
+};
+
+// Tailwind-kompatible Farbpalette für die Verwendung in der tailwind.config.js
+export const tailwindColors = {
+  // Light Mode Colors
+  light: {
+    primary: '#0A84FF',
+    secondary: '#5E5CE6',
+    background: '#F2F2F7',
+    card: '#FFFFFF',
+    text: '#000000',
+    border: '#E5E5EA',
+    notification: '#FF3B30',
+    placeholder: '#8E8E93',
+    accent: '#34C759',
+    muted: '#C7C7CC',
+    buttonHover: 'rgba(255, 255, 255, 0.7)',
+    menuItemHover: 'rgba(255, 255, 255, 0.5)',
+    cardHover: 'rgba(255, 255, 255, 0.3)',
+    dangerHover: 'rgba(255, 255, 255, 0.5)',
+  },
+  // Dark Mode Colors
+  dark: {
+    primary: '#0A84FF',
+    secondary: '#5E5CE6',
+    background: '#1C1C1E',
+    card: '#2C2C2E',
+    text: '#FFFFFF',
+    border: '#38383A',
+    notification: '#FF453A',
+    placeholder: '#8E8E93',
+    accent: '#30D158',
+    muted: '#48484A',
+    buttonHover: 'rgba(255, 255, 255, 0.15)',
+    menuItemHover: 'rgba(255, 255, 255, 0.1)',
+    cardHover: 'rgba(255, 255, 255, 0.05)',
+    dangerHover: 'rgba(255, 255, 255, 0.15)',
+  },
+};