docs: Clean up obsolete docs and create Customer SPA Master Plan

Documentation Cleanup:
✅ Archived 6 obsolete/completed docs to archive/:
- CUSTOMER_DATA_FLOW_ANALYSIS.md
- CALCULATION_EFFICIENCY_AUDIT.md
- PHASE_COMPLETE.md
- PRODUCT_FORM_UX_IMPROVEMENTS.md
- PROGRESS_NOTE.md
- TASKS_SUMMARY.md

New Documentation:
✅ CUSTOMER_SPA_MASTER_PLAN.md - Comprehensive strategy

Includes:
1. Architecture Overview
   - Hybrid plugin architecture
   - customer-spa folder structure
   - Frontend/Backend separation

2. Deployment Modes
   - Shortcode Mode (default, works with any theme)
   - Full SPA Mode (maximum performance)
   - Hybrid Mode (best of both worlds)

3. Feature Scope
   - Phase 1: Core Commerce (MVP)
   - Phase 2: Enhanced Features
   - Phase 3: Advanced Features

4. UX Best Practices
   - Research-backed patterns (Baymard Institute)
   - Cart UX (drawer, mini cart, shipping threshold)
   - Checkout UX (progress, guest, autocomplete)
   - Product Page UX (images, CTA, social proof)

5. Technical Stack
   - React 18 + Vite
   - Zustand + React Query
   - TailwindCSS + shadcn/ui
   - PWA with Workbox

6. Implementation Roadmap
   - 10 sprints (20 weeks)
   - Foundation → Catalog → Cart → Account → Polish

7. API Requirements
   - 15+ new endpoints needed
   - Shop, Cart, Checkout, Account APIs

8. Performance Targets
   - Core Web Vitals
   - Bundle sizes
   - Load times

9. Settings & Configuration
   - Frontend mode selection
   - Feature toggles
   - Customization options

10. Migration Strategy
    - From WooCommerce default
    - Rollback plan
    - Success metrics

Result: Clear, actionable plan for Customer SPA development!

archive/TASKS_SUMMARY.md

@@ -0,0 +1,130 @@
+# Tasks Summary - November 11, 2025
+
+## ✅ Task 1: Translation Support Audit
+
+### Status: COMPLETED ✓
+
+**Findings:**
+- Most settings pages already have `__` translation function imported
+- **Missing translation support:**
+  - `Store.tsx` - Needs `__` import and string wrapping
+  - `Payments.tsx` - Needs `__` import and string wrapping  
+  - `Developer.tsx` - Needs `__` import and string wrapping
+
+**Action Required:**
+Add translation support to these 3 files (can be done during next iteration)
+
+---
+
+## ✅ Task 2: Documentation Audit
+
+### Status: COMPLETED ✓
+
+**Actions Taken:**
+1. ✅ Created `DOCS_AUDIT_REPORT.md` - Comprehensive audit of all 36 MD files
+2. ✅ Deleted 12 obsolete documents:
+   - CUSTOMER_SETTINGS_404_FIX.md
+   - MENU_FIX_SUMMARY.md
+   - DASHBOARD_TWEAKS_TODO.md
+   - DASHBOARD_PLAN.md
+   - SPA_ADMIN_MENU_PLAN.md
+   - STANDALONE_ADMIN_SETUP.md
+   - STANDALONE_MODE_SUMMARY.md
+   - SETTINGS_PAGES_PLAN.md
+   - SETTINGS_PAGES_PLAN_V2.md
+   - SETTINGS_TREE_PLAN.md
+   - SETTINGS_PLACEMENT_STRATEGY.md
+   - TAX_NOTIFICATIONS_PLAN.md
+
+**Result:**
+- Reduced from 36 to 24 documents (33% reduction)
+- Clearer focus on active development
+- Easier navigation for developers
+
+**Remaining Documents:**
+- 15 essential docs (keep as-is)
+- 9 docs to consolidate later (low priority)
+
+---
+
+## 🚧 Task 3: Notification Settings Implementation
+
+### Status: IN PROGRESS
+
+**Plan:** Follow NOTIFICATION_STRATEGY.md
+
+### Phase 1: Core Framework (Current)
+1. **Backend (PHP)**
+   - [ ] Create `NotificationManager` class
+   - [ ] Create `EmailChannel` class (built-in)
+   - [ ] Create notification events registry
+   - [ ] Create REST API endpoints
+   - [ ] Add hooks for addon integration
+
+2. **Frontend (React)**
+   - [ ] Update `Notifications.tsx` settings page
+   - [ ] Create channel cards UI
+   - [ ] Create event configuration UI
+   - [ ] Add channel toggle/enable functionality
+   - [ ] Add template editor (email)
+
+3. **Database**
+   - [ ] Notification events table (optional)
+   - [ ] Use wp_options for settings
+   - [ ] Channel configurations
+
+### Implementation Steps
+
+#### Step 1: Backend Core
+```
+includes/Core/Notifications/
+├── NotificationManager.php      # Main manager
+├── NotificationEvent.php        # Event class
+├── Channels/
+│   └── EmailChannel.php         # Built-in email
+└── NotificationSettingsProvider.php  # Settings CRUD
+```
+
+#### Step 2: REST API
+```
+includes/Api/NotificationsController.php
+- GET /notifications/channels    # List available channels
+- GET /notifications/events      # List notification events
+- GET /notifications/settings    # Get all settings
+- POST /notifications/settings   # Save settings
+```
+
+#### Step 3: Frontend UI
+```
+admin-spa/src/routes/Settings/Notifications.tsx
+- Channel cards (email + addon channels)
+- Event configuration per category
+- Toggle channels per event
+- Recipient selection (admin/customer/both)
+```
+
+### Key Features
+- ✅ Email channel built-in
+- ✅ Addon integration via hooks
+- ✅ Per-event channel selection
+- ✅ Recipient targeting
+- ✅ Template system ready
+
+---
+
+## Next Actions
+
+### Immediate
+1. ✅ Commit documentation cleanup
+2. 🚧 Start notification system implementation
+3. ⏳ Add translation to Store/Payments/Developer pages
+
+### This Session
+- Implement notification core framework
+- Create REST API endpoints
+- Build basic UI for notification settings
+
+### Future
+- Build Telegram addon as proof of concept
+- Create addon development template
+- Document notification addon API