refactor: rename public routes and templates to platform

Complete the public -> platform naming migration across the codebase.
This aligns with the naming convention where "platform" refers to
the marketing/public-facing pages of the platform itself.

Changes:
- Update all imports from public to platform modules
- Update template references from public/ to platform/
- Update route registrations to use platform prefix
- Update documentation to reflect new naming
- Update test files for platform API endpoints

Files affected:
- app/api/main.py - router imports
- app/modules/*/routes/*/platform.py - route definitions
- app/modules/*/templates/*/platform/ - template files
- app/modules/routes.py - route discovery
- docs/* - documentation updates
- tests/integration/api/v1/platform/ - test files

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docs/architecture/api-migration-status.md

@@ -174,15 +174,15 @@ Updated all shop templates to use new API endpoints:
 
 | Template | Old Endpoint | New Endpoint | Status |
 |----------|-------------|--------------|---------|
-| `shop/account/login.html` | `/api/v1/public/vendors/${id}/customers/login` | `/api/v1/shop/auth/login` | ✅ Complete |
-| `shop/account/register.html` | `/api/v1/public/vendors/${id}/customers/register` | `/api/v1/shop/auth/register` | ✅ Complete |
-| `shop/product.html` | `/api/v1/public/vendors/${id}/products/${pid}` | `/api/v1/shop/products/${pid}` | ✅ Complete |
-| `shop/product.html` | `/api/v1/public/vendors/${id}/products?limit=4` | `/api/v1/shop/products?limit=4` | ✅ Complete |
-| `shop/product.html` | `/api/v1/public/vendors/${id}/cart/${sid}` | `/api/v1/shop/cart/${sid}` | ✅ Complete |
-| `shop/product.html` | `/api/v1/public/vendors/${id}/cart/${sid}/items` | `/api/v1/shop/cart/${sid}/items` | ✅ Complete |
-| `shop/cart.html` | `/api/v1/public/vendors/${id}/cart/${sid}` | `/api/v1/shop/cart/${sid}` | ✅ Complete |
-| `shop/cart.html` | `/api/v1/public/vendors/${id}/cart/${sid}/items/${pid}` (PUT) | `/api/v1/shop/cart/${sid}/items/${pid}` | ✅ Complete |
-| `shop/cart.html` | `/api/v1/public/vendors/${id}/cart/${sid}/items/${pid}` (DELETE) | `/api/v1/shop/cart/${sid}/items/${pid}` | ✅ Complete |
+| `shop/account/login.html` | `/api/v1/platform/vendors/${id}/customers/login` | `/api/v1/shop/auth/login` | ✅ Complete |
+| `shop/account/register.html` | `/api/v1/platform/vendors/${id}/customers/register` | `/api/v1/shop/auth/register` | ✅ Complete |
+| `shop/product.html` | `/api/v1/platform/vendors/${id}/products/${pid}` | `/api/v1/shop/products/${pid}` | ✅ Complete |
+| `shop/product.html` | `/api/v1/platform/vendors/${id}/products?limit=4` | `/api/v1/shop/products?limit=4` | ✅ Complete |
+| `shop/product.html` | `/api/v1/platform/vendors/${id}/cart/${sid}` | `/api/v1/shop/cart/${sid}` | ✅ Complete |
+| `shop/product.html` | `/api/v1/platform/vendors/${id}/cart/${sid}/items` | `/api/v1/shop/cart/${sid}/items` | ✅ Complete |
+| `shop/cart.html` | `/api/v1/platform/vendors/${id}/cart/${sid}` | `/api/v1/shop/cart/${sid}` | ✅ Complete |
+| `shop/cart.html` | `/api/v1/platform/vendors/${id}/cart/${sid}/items/${pid}` (PUT) | `/api/v1/shop/cart/${sid}/items/${pid}` | ✅ Complete |
+| `shop/cart.html` | `/api/v1/platform/vendors/${id}/cart/${sid}/items/${pid}` (DELETE) | `/api/v1/shop/cart/${sid}/items/${pid}` | ✅ Complete |
 | `shop/products.html` | Already using `/api/v1/shop/products` | (No change needed) | ✅ Already Updated |
 | `shop/home.html` | Already using `/api/v1/shop/products?featured=true` | (No change needed) | ✅ Already Updated |
 
@@ -196,7 +196,7 @@ grep -r "api/v1/public/vendors" app/templates/shop --include="*.html"
 
 ### ✅ Phase 3: Old Endpoint Cleanup (COMPLETE)
 
-Cleaned up old `/api/v1/public/vendors/*` endpoints:
+Cleaned up old `/api/v1/platform/vendors/*` endpoints:
 
 **Files Removed:**
 - ❌ `auth.py` - Migrated to `/api/v1/shop/auth.py`
@@ -209,14 +209,14 @@ Cleaned up old `/api/v1/public/vendors/*` endpoints:
 
 **Files Kept:**
 - ✅ `vendors.py` - Vendor lookup endpoints (truly public, not shop-specific)
-  - `GET /api/v1/public/vendors/by-code/{vendor_code}`
-  - `GET /api/v1/public/vendors/by-subdomain/{subdomain}`
-  - `GET /api/v1/public/vendors/{vendor_id}/info`
+  - `GET /api/v1/platform/vendors/by-code/{vendor_code}`
+  - `GET /api/v1/platform/vendors/by-subdomain/{subdomain}`
+  - `GET /api/v1/platform/vendors/{vendor_id}/info`
 
 **Updated:**
-- ✅ `/app/api/v1/public/__init__.py` - Now only includes vendor lookup endpoints
+- ✅ `/app/api/v1/platform/__init__.py` - Now only includes vendor lookup endpoints
 
-**Result:** Old shop endpoints completely removed, only vendor lookup remains in `/api/v1/public/vendors/*`
+**Result:** Old shop endpoints completely removed, only vendor lookup remains in `/api/v1/platform/vendors/*`
 
 ### ⚠️ Phase 4: Deprecation Warnings (SKIPPED - Not Needed)
 
@@ -252,16 +252,16 @@ Old endpoint cleanup completed immediately (no gradual migration needed):
 
 1. ✅ Removed old endpoint files:
    ```bash
-   rm app/api/v1/public/vendors/products.py
-   rm app/api/v1/public/vendors/cart.py
-   rm app/api/v1/public/vendors/orders.py
-   rm app/api/v1/public/vendors/auth.py
-   rm app/api/v1/public/vendors/payments.py
-   rm app/api/v1/public/vendors/search.py
-   rm app/api/v1/public/vendors/shop.py
+   rm app/api/v1/platform/vendors/products.py
+   rm app/api/v1/platform/vendors/cart.py
+   rm app/api/v1/platform/vendors/orders.py
+   rm app/api/v1/platform/vendors/auth.py
+   rm app/api/v1/platform/vendors/payments.py
+   rm app/api/v1/platform/vendors/search.py
+   rm app/api/v1/platform/vendors/shop.py
    ```
 
-2. ✅ Updated `/api/v1/public/__init__.py`:
+2. ✅ Updated `/api/v1/platform/__init__.py`:
    ```python
    # Only import vendor lookup endpoints
    from .vendors import vendors
@@ -280,12 +280,12 @@ Old endpoint cleanup completed immediately (no gradual migration needed):
 ### Before (Old Pattern)
 ```
 # Verbose - requires vendor_id everywhere
-/api/v1/public/vendors/123/products
-/api/v1/public/vendors/123/products/456
-/api/v1/public/vendors/123/cart/abc-session-id
-/api/v1/public/vendors/123/cart/abc-session-id/items
-/api/v1/public/vendors/123/customers/789/orders
-/api/v1/public/vendors/auth/123/customers/login
+/api/v1/platform/vendors/123/products
+/api/v1/platform/vendors/123/products/456
+/api/v1/platform/vendors/123/cart/abc-session-id
+/api/v1/platform/vendors/123/cart/abc-session-id/items
+/api/v1/platform/vendors/123/customers/789/orders
+/api/v1/platform/vendors/auth/123/customers/login
 ```
 
 ### After (New Pattern)