chore: mark US-015 as complete and update progress log

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

prd.json

@@ -261,7 +261,7 @@
         "Verify in browser using dev-browser skill"
       ],
       "priority": 15,
-      "passes": false,
+      "passes": true,
       "notes": ""
     },
     {

progress.txt

@@ -224,3 +224,18 @@
   - Toast animations can use TailwindCSS animate-in utilities (fade-in, slide-in-from-bottom-4)
   - Delete icon appears on hover using group-hover:opacity-100 with parent group class
 ---
+
+## 2026-01-21 - US-015
+- What was implemented: Rename project functionality
+- Files changed:
+  - src/components/ProjectCard.tsx - added rename button, modal dialog, and Supabase update logic
+  - src/components/ProjectList.tsx - added handleRename callback and toast notification
+- **Learnings for future iterations:**
+  - Multiple action buttons on a card can be grouped in a flex container with gap-1
+  - Rename modal follows same pattern as delete dialog: fixed positioning, backdrop, form
+  - Use onKeyDown to handle Enter key for quick form submission
+  - Reset form state (newName, error) when opening modal to handle edge cases
+  - Check if name is unchanged before making API call to avoid unnecessary requests
+  - Trim whitespace from input value before validation and submission
+  - handleRename callback updates project name in state using map() to preserve list order
+---