Add portfolio template to combined marketing+portfolio template

- Added portfolio pages: portfolio-index, portfolio-about, portfolio-contact
- Added work/[slug].astro for project detail pages
- Added PortfolioBase.astro layout with Playfair Display font
- Added ProjectCard.astro component
- Added projects collection with taxonomies (category, tag)
- Updated theme.css with --font-serif variable
- Added portfolio seed data with 4 projects
- Updated menus to include Work link

.omc/state/checkpoints/checkpoint-2026-05-01T06-12-29-591Z.json

@@ -0,0 +1,16 @@
+{
+  "created_at": "2026-05-01T06:12:29.590Z",
+  "trigger": "auto",
+  "active_modes": {},
+  "todo_summary": {
+    "pending": 0,
+    "in_progress": 0,
+    "completed": 0
+  },
+  "wisdom_exported": false,
+  "background_jobs": {
+    "active": [],
+    "recent": [],
+    "stats": null
+  }
+}