Add delete with confirmation for trips and dashcam

- Confirmation modal in server base.html (window.confirmDelete promise helper)
- Trip delete: trash button in Replay column (server-only via data-deletable on
  trip-list div), DELETE /api/v1/portal/trip/<id>, removes computed trip only
  (raw tracking_points kept)
- Dashcam delete: trash button next to download, DELETE /api/v1/portal/dashcam/<id>,
  removes from DB + disk (best-effort file removal)
- history.js: delete button gated on data-deletable='1' attribute; click handler
  intercepts before replay logic
- db.py: delete_trip(), delete_dashcam_file() helpers

Co-authored-by: Copilot <[email protected]>

server/templates/dashcam.html

@@ -133,13 +133,17 @@ async function loadFiles() {
                     <td class="text-truncate" style="max-width:200px;" title="${f.relative_path}">${name}</td>
                     <td class="text-nowrap">${fmtSize(f.size_bytes)}</td>
                     <td class="text-nowrap d-none d-sm-table-cell">${fmtDate(f.uploaded_at)}</td>
-                    <td class="text-end">
+            <td class="text-end text-nowrap">
                         <a href="/api/v1/portal/dashcam/stream/${f.id}" download="${name}"
                            class="btn btn-outline-secondary btn-sm py-0 px-1" title="Download"
                            onclick="event.stopPropagation()">
                             <i class="fas fa-download fa-fw"></i>
                         </a>
-                    </td>
+                <button class="btn btn-outline-danger btn-sm py-0 px-1 ms-1" title="Delete"
+                        onclick="event.stopPropagation(); deleteFile(${f.id}, '${name.replace(/'/g,"\\'")}')">
+                    <i class="fas fa-trash fa-fw"></i>
+                </button>
+            </td>
                 </tr>
             `;
         }).join('');
@@ -152,5 +156,28 @@ async function loadFiles() {
 }
 
 loadFiles();
+
+async function deleteFile(id, name) {
+    const confirmed = await window.confirmDelete(`Delete "${name}"? This removes the file from disk permanently.`);
+    if (!confirmed) return;
+    const res = await fetch(`/api/v1/portal/dashcam/${id}`, { method: 'DELETE' });
+    if (!res.ok) { alert('Delete failed.'); return; }
+    // Clear player if this file was playing
+    const player = document.getElementById('video-player');
+    if (currentFileId === id) {
+        player.pause();
+        player.src = '';
+        player.hidden = true;
+        document.getElementById('player-placeholder').hidden = false;
+        document.getElementById('player-meta').hidden = true;
+        document.getElementById('btn-download').hidden = true;
+        currentFileId = null;
+    }
+    // Remove row
+    const row = document.querySelector(`#files-body tr[data-file-id="${id}"]`);
+    if (row) row.remove();
+    const countEl = document.getElementById('file-count');
+    countEl.textContent = parseInt(countEl.textContent) - 1;
+}
 </script>
 {% endblock %}