feat: Implement Phase 2, 3, 4 - Module Settings System with Schema Forms and Addon API

Phase 2: Schema-Based Form System
- Add ModuleSettingsController with GET/POST/schema endpoints
- Create SchemaField component supporting 8 field types (text, textarea, email, url, number, toggle, checkbox, select)
- Create SchemaForm component for automatic form generation from schema
- Add ModuleSettings page with dynamic routing (/settings/modules/:moduleId)
- Add useModuleSettings React hook for settings management
- Implement NewsletterSettings as example with 8 configurable fields
- Add has_settings flag to module registry
- Settings stored as woonoow_module_{module_id}_settings

Phase 3: Advanced Features
- Create windowAPI.ts exposing React, hooks, components, icons, utils to addons via window.WooNooW
- Add DynamicComponentLoader for loading external React components
- Create TypeScript definitions (woonoow-addon.d.ts) for addon developers
- Initialize Window API in App.tsx on mount
- Enable custom React components for addon settings pages

Phase 4: Production Polish & Example
- Create complete Biteship addon example demonstrating both approaches:
  * Schema-based settings (no build required)
  * Custom React component (with build)
- Add comprehensive README with installation and testing guide
- Include package.json with esbuild configuration
- Demonstrate window.WooNooW API usage in custom component

Bug Fixes:
- Fix footer newsletter form visibility (remove redundant module check)
- Fix footer contact_data and social_links not saving (parameter name mismatch: snake_case vs camelCase)
- Fix useModules hook returning undefined (remove .data wrapper, add fallback)
- Add optional chaining to footer settings rendering
- Fix TypeScript errors in woonoow-addon.d.ts (use any for external types)

Files Added (15):
- includes/Api/ModuleSettingsController.php
- includes/Modules/NewsletterSettings.php
- admin-spa/src/components/forms/SchemaField.tsx
- admin-spa/src/components/forms/SchemaForm.tsx
- admin-spa/src/routes/Settings/ModuleSettings.tsx
- admin-spa/src/hooks/useModuleSettings.ts
- admin-spa/src/lib/windowAPI.ts
- admin-spa/src/components/DynamicComponentLoader.tsx
- types/woonoow-addon.d.ts
- examples/biteship-addon/biteship-addon.php
- examples/biteship-addon/src/Settings.jsx
- examples/biteship-addon/package.json
- examples/biteship-addon/README.md
- PHASE_2_3_4_SUMMARY.md

Files Modified (11):
- admin-spa/src/App.tsx
- admin-spa/src/hooks/useModules.ts
- admin-spa/src/routes/Appearance/Footer.tsx
- admin-spa/src/routes/Settings/Modules.tsx
- customer-spa/src/hooks/useModules.ts
- customer-spa/src/layouts/BaseLayout.tsx
- customer-spa/src/components/NewsletterForm.tsx
- includes/Api/Routes.php
- includes/Api/ModulesController.php
- includes/Core/ModuleRegistry.php
- woonoow.php

API Endpoints Added:
- GET /woonoow/v1/modules/{module_id}/settings
- POST /woonoow/v1/modules/{module_id}/settings
- GET /woonoow/v1/modules/{module_id}/schema

For Addon Developers:
- Schema-based: Define settings via woonoow/module_settings_schema filter
- Custom React: Build component using window.WooNooW API, externalize react/react-dom
- Both approaches use same storage and retrieval methods
- TypeScript definitions provided for type safety
- Complete working example (Biteship) included

admin-spa/src/lib/windowAPI.ts

@@ -0,0 +1,200 @@
+/**
+ * WooNooW Window API
+ * 
+ * Exposes React, hooks, components, and utilities to addon developers
+ * via window.WooNooW object
+ */
+
+import React from 'react';
+import ReactDOM from 'react-dom/client';
+import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
+import { toast } from 'sonner';
+
+// UI Components
+import { Button } from '@/components/ui/button';
+import { Input } from '@/components/ui/input';
+import { Label } from '@/components/ui/label';
+import { Textarea } from '@/components/ui/textarea';
+import { Switch } from '@/components/ui/switch';
+import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from '@/components/ui/select';
+import { Checkbox } from '@/components/ui/checkbox';
+import { Badge } from '@/components/ui/badge';
+import { Card, CardContent, CardDescription, CardFooter, CardHeader, CardTitle } from '@/components/ui/card';
+
+// Settings Components
+import { SettingsLayout } from '@/routes/Settings/components/SettingsLayout';
+import { SettingsCard } from '@/routes/Settings/components/SettingsCard';
+import { SettingsSection } from '@/routes/Settings/components/SettingsSection';
+
+// Form Components
+import { SchemaForm } from '@/components/forms/SchemaForm';
+import { SchemaField } from '@/components/forms/SchemaField';
+
+// Hooks
+import { useModules } from '@/hooks/useModules';
+import { useModuleSettings } from '@/hooks/useModuleSettings';
+
+// Utils
+import { api } from '@/lib/api';
+import { __ } from '@/lib/i18n';
+
+// Icons (commonly used)
+import { 
+  Settings, 
+  Save, 
+  Trash2, 
+  Edit, 
+  Plus, 
+  X, 
+  Check, 
+  AlertCircle,
+  Info,
+  Loader2,
+  ChevronDown,
+  ChevronUp,
+  ChevronLeft,
+  ChevronRight,
+} from 'lucide-react';
+
+/**
+ * WooNooW Window API Interface
+ */
+export interface WooNooWAPI {
+  React: typeof React;
+  ReactDOM: typeof ReactDOM;
+  
+  hooks: {
+    useQuery: typeof useQuery;
+    useMutation: typeof useMutation;
+    useQueryClient: typeof useQueryClient;
+    useModules: typeof useModules;
+    useModuleSettings: typeof useModuleSettings;
+  };
+  
+  components: {
+    // Basic UI
+    Button: typeof Button;
+    Input: typeof Input;
+    Label: typeof Label;
+    Textarea: typeof Textarea;
+    Switch: typeof Switch;
+    Select: typeof Select;
+    SelectContent: typeof SelectContent;
+    SelectItem: typeof SelectItem;
+    SelectTrigger: typeof SelectTrigger;
+    SelectValue: typeof SelectValue;
+    Checkbox: typeof Checkbox;
+    Badge: typeof Badge;
+    Card: typeof Card;
+    CardContent: typeof CardContent;
+    CardDescription: typeof CardDescription;
+    CardFooter: typeof CardFooter;
+    CardHeader: typeof CardHeader;
+    CardTitle: typeof CardTitle;
+    
+    // Settings Components
+    SettingsLayout: typeof SettingsLayout;
+    SettingsCard: typeof SettingsCard;
+    SettingsSection: typeof SettingsSection;
+    
+    // Form Components
+    SchemaForm: typeof SchemaForm;
+    SchemaField: typeof SchemaField;
+  };
+  
+  icons: {
+    Settings: typeof Settings;
+    Save: typeof Save;
+    Trash2: typeof Trash2;
+    Edit: typeof Edit;
+    Plus: typeof Plus;
+    X: typeof X;
+    Check: typeof Check;
+    AlertCircle: typeof AlertCircle;
+    Info: typeof Info;
+    Loader2: typeof Loader2;
+    ChevronDown: typeof ChevronDown;
+    ChevronUp: typeof ChevronUp;
+    ChevronLeft: typeof ChevronLeft;
+    ChevronRight: typeof ChevronRight;
+  };
+  
+  utils: {
+    api: typeof api;
+    toast: typeof toast;
+    __: typeof __;
+  };
+}
+
+/**
+ * Initialize Window API
+ * Exposes WooNooW API to window object for addon developers
+ */
+export function initializeWindowAPI() {
+  const windowAPI: WooNooWAPI = {
+    React,
+    ReactDOM,
+    
+    hooks: {
+      useQuery,
+      useMutation,
+      useQueryClient,
+      useModules,
+      useModuleSettings,
+    },
+    
+    components: {
+      Button,
+      Input,
+      Label,
+      Textarea,
+      Switch,
+      Select,
+      SelectContent,
+      SelectItem,
+      SelectTrigger,
+      SelectValue,
+      Checkbox,
+      Badge,
+      Card,
+      CardContent,
+      CardDescription,
+      CardFooter,
+      CardHeader,
+      CardTitle,
+      SettingsLayout,
+      SettingsCard,
+      SettingsSection,
+      SchemaForm,
+      SchemaField,
+    },
+    
+    icons: {
+      Settings,
+      Save,
+      Trash2,
+      Edit,
+      Plus,
+      X,
+      Check,
+      AlertCircle,
+      Info,
+      Loader2,
+      ChevronDown,
+      ChevronUp,
+      ChevronLeft,
+      ChevronRight,
+    },
+    
+    utils: {
+      api,
+      toast,
+      __,
+    },
+  };
+  
+  // Expose to window
+  (window as any).WooNooW = windowAPI;
+  
+  console.log('✅ WooNooW API initialized for addon developers');
+}