chore: add shared components and update docs

- Add vendor selector component for admin pages
- Add input macros for form handling
- Add truck icon for shipping UI
- Update vendor operations expansion plan
- Update mkdocs configuration
- Update dependencies

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

pyproject.toml

@@ -142,8 +142,9 @@ markers = [
     "performance: marks tests as performance and load tests",
     "auth: marks tests as authentication and authorization tests",
     "products: marks tests as product management functionality",
-    "inventory: marks tests as inventory and inventory management",
-    "vendors: marks tests as vendor management functionality",
+    "inventory: marks tests as inventory and stock management",
+    "vendors: marks tests as vendor management (plural - admin context)",
+    "vendor: marks tests as vendor API tests (singular - vendor context)",
     "admin: marks tests as admin functionality and permissions",
     "marketplace: marks tests as marketplace import functionality",
     "stats: marks tests as statistics and reporting",