Add delete button to project list on main page

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/App.css

@@ -70,6 +70,22 @@ h2 {
   font-size: 0.85rem;
 }
 
+.project-delete {
+  background: #c0392b;
+  color: white;
+  border: none;
+  border-radius: 4px;
+  padding: 0.2rem 0.5rem;
+  font-size: 0.8rem;
+  cursor: pointer;
+  margin-left: 0.5rem;
+  flex-shrink: 0;
+}
+
+.project-delete:hover {
+  background: #e74c3c;
+}
+
 .back-btn {
   padding: 0.4rem 1rem;
   font-size: 0.9rem;

frontend/src/App.tsx

@@ -54,6 +54,16 @@ function ProjectList({
             <span className="project-date">
               {new Date(p.created_at).toLocaleString()}
             </span>
+            <button
+              className="project-delete"
+              onClick={async (e) => {
+                e.stopPropagation();
+                await deleteProject(p.id);
+                await load();
+              }}
+            >
+              X
+            </button>
           </div>
         ))}
       </div>