docs: Update all documentation for standalone mode and settings structure

PROGRESS_NOTE.md

@@ -2062,3 +2062,166 @@ All endpoints support caching (5 minutes):
 **Total Development Time:** ~6 hours  
 **Status:** ✅ Production Ready  
 **Next Milestone:** Products module OR Settings module
+
+---
+
+## 🚀 Standalone Admin Mode — November 5, 2025
+
+### ✅ COMPLETE - Three Admin Modes Implemented
+
+**Goal:** Provide flexible admin interface access with three distinct modes: normal (wp-admin), fullscreen, and standalone.
+
+### 🎯 Three Admin Modes
+
+#### **1. Normal Mode (wp-admin)**
+- **URL:** `/wp-admin/admin.php?page=woonoow`
+- **Layout:** WordPress admin sidebar + WooNooW SPA
+- **Use Case:** Traditional WordPress admin workflow
+- **Features:**
+  - WordPress admin bar visible
+  - WordPress sidebar navigation
+  - WooNooW SPA in main content area
+  - Settings submenu hidden (use WooCommerce settings)
+
+#### **2. Fullscreen Mode**
+- **Toggle:** Fullscreen button in header
+- **Layout:** WooNooW SPA only (no WordPress chrome)
+- **Use Case:** Focus mode for order processing
+- **Features:**
+  - Maximized workspace
+  - Distraction-free interface
+  - All WooNooW features accessible
+  - Settings submenu hidden
+
+#### **3. Standalone Mode** ✨ NEW
+- **URL:** `https://yoursite.com/admin`
+- **Layout:** Complete standalone application
+- **Use Case:** Quick daily access, mobile-friendly
+- **Features:**
+  - Custom login page (`/admin#/login`)
+  - WordPress authentication integration
+  - Settings submenu visible (SPA settings pages)
+  - "WordPress" button to access wp-admin
+  - "Logout" button in header
+  - Admin bar link in wp-admin to standalone
+
+### 🔧 Implementation Details
+
+#### **Backend Changes**
+
+**File:** `includes/Admin/StandaloneAdmin.php`
+- Handles `/admin` and `/admin/` requests
+- Renders standalone HTML template
+- Localizes `WNW_CONFIG` with `standaloneMode: true`
+- Provides authentication state
+- Includes store settings (currency, formatting)
+
+**File:** `includes/Admin/Menu.php`
+- Added admin bar link to standalone mode
+- Icon: `dashicons-store`
+- Only visible to users with `manage_woocommerce` capability
+
+**File:** `includes/Api/AuthController.php`
+- Login endpoint using native WordPress authentication
+- Sequence: `wp_authenticate()` → `wp_clear_auth_cookie()` → `wp_set_current_user()` → `wp_set_auth_cookie()` → `do_action('wp_login')`
+- Ensures session persistence between standalone and wp-admin
+
+#### **Frontend Changes**
+
+**File:** `admin-spa/src/App.tsx`
+- `AuthWrapper` component handles authentication
+- Login/logout flow with page reload
+- "WordPress" button in header (standalone only)
+- "Logout" button in header (standalone only)
+
+**File:** `admin-spa/src/routes/Login.tsx`
+- Custom login form
+- Username/password authentication
+- Redirects to dashboard after login
+- Page reload to pick up fresh cookies/nonces
+
+**File:** `admin-spa/src/nav/tree.ts`
+- Dynamic settings submenu using getter
+- Only shows in standalone mode: `get children() { return isStandalone ? [...] : [] }`
+- Dashboard path: `/dashboard` (with redirect from `/`)
+
+### 📊 Navigation Structure
+
+**Standalone Mode Settings:**
+```
+Settings
+├── WooNooW (main settings)
+├── General (store settings)
+├── Payments (gateways)
+├── Shipping (zones, methods)
+├── Products (inventory)
+├── Tax (rates)
+├── Accounts & Privacy
+├── Emails (templates)
+├── Advanced (bridge to wp-admin)
+├── Integration (bridge to wp-admin)
+├── Status (bridge to wp-admin)
+└── Extensions (bridge to wp-admin)
+```
+
+**Strategy:** Option A - Everyday Use Dashboard
+- Focus on most-used settings
+- Bridge to wp-admin for advanced settings
+- Extensible for 3rd party plugins
+- Coexist with WooCommerce
+
+### 🔐 Authentication Flow
+
+**Standalone Login:**
+1. User visits `/admin`
+2. Not authenticated → redirect to `/admin#/login`
+3. Submit credentials → `POST /wp-json/woonoow/v1/auth/login`
+4. Backend sets WordPress auth cookies
+5. Page reload → authenticated state
+6. Access all WooNooW features
+
+**Session Persistence:**
+- Login in standalone → logged in wp-admin ✅
+- Login in wp-admin → logged in standalone ✅
+- Logout in standalone → logged out wp-admin ✅
+- Logout in wp-admin → logged out standalone ✅
+
+### 📱 Cross-Navigation
+
+**From Standalone to wp-admin:**
+- Click "WordPress" button in header
+- Opens `/wp-admin` in same tab
+- Session persists
+
+**From wp-admin to Standalone:**
+- Click "WooNooW" in admin bar
+- Opens `/admin` in same tab
+- Session persists
+
+### ✅ Features Completed
+
+- [x] Standalone mode routing (`/admin`)
+- [x] Custom login page
+- [x] WordPress authentication integration
+- [x] Session persistence
+- [x] Settings submenu (standalone only)
+- [x] WordPress button in header
+- [x] Logout button in header
+- [x] Admin bar link to standalone
+- [x] Dashboard path consistency (`/dashboard`)
+- [x] Dynamic navigation tree
+- [x] Settings placeholder pages
+- [x] Documentation updates
+
+### 📚 Documentation
+
+- `STANDALONE_ADMIN_SETUP.md` - Setup guide
+- `PROJECT_BRIEF.md` - Updated Phase 4
+- `PROJECT_SOP.md` - Section 7 (modes explanation)
+- `PROGRESS_NOTE.md` - This section
+
+---
+
+**Implementation Date:** November 5, 2025  
+**Status:** ✅ Production Ready  
+**Next Milestone:** Implement General/Payments/Shipping settings pages