docs: update ROADMAP with completed items

Mark as completed:
- Navigation links between admin and shop
- Collection routes with filtering and sorting
- Header navigation accessibility improvements

Update Phase 9 routes to reflect current implementation.

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

ROADMAP.md

@@ -339,22 +339,6 @@ This ensures sellers never unknowingly sell at a loss due to Printify price chan
 
 ## Quick Wins (Low Effort)
 
-### Navigation Links Between Admin and Shop
-**Status:** Not implemented
-**Effort:** Small
-
-No links exist to navigate between the theme editor (`/admin/theme`) and the public shop (`/`).
-
-**Implementation:**
-- Add "View Shop" button in theme editor header
-- Add "Edit Theme" link in shop header (when authenticated)
-
-### Collection Slug Routes
-**Status:** Partial
-**Effort:** Small
-
-Currently we have `/products` but the original plan included `/collections/:slug` for filtered views by category.
-
 ### Enhanced Contact Page
 **Status:** Not implemented
 **Effort:** Small
@@ -479,7 +463,7 @@ The project is currently named `simpleshop_theme` (reflecting its origins as a t
 - Preview system with 7 pages
 
 ### Phase 9: Storefront Integration ✅
-- Public shop routes (/, /products, /products/:id, /cart, /about, /contact)
+- Public shop routes (/, /collections/:slug, /products/:id, /cart, /about, /contact)
 - Shared PageTemplates for shop and preview
 - CSS injection via shop layout
 - Themed error pages (404/500)
@@ -488,3 +472,19 @@ The project is currently named `simpleshop_theme` (reflecting its origins as a t
 ### CSS Cache Warming on Startup ✅
 - ETS cache pre-warmed in `CSSCache.init/1`
 - First request doesn't need to generate CSS
+
+### Navigation Links Between Admin and Shop ✅
+- "View Shop" button in theme editor header
+- Collapsible navigation sidebar in theme editor
+
+### Collection Routes with Filtering & Sorting ✅
+- `/collections/:slug` routes for category filtering
+- `/collections/all` for all products
+- Product sorting (featured, newest, price, name)
+- Sort parameter preserved in URL across navigation
+- Category filter pills with sort persistence
+
+### Header Navigation Accessibility ✅
+- Current page is not a link (avoids self-links)
+- Logo links to home except when on home page
+- `aria-current="page"` with visual underline indicator