feat: Vibration Events sub-tab + last-event on location cards

Two additions to the project Vibration tab:

- Events sub-tab (next to Locations): a project-wide events table across all
  vibration locations. New GET /api/projects/{id}/vibration-events fans
  events_for_location across the project's vibration locations, tags each event
  with its location, and merges newest-first (From/To date filters, Real/FT
  filter, limit). Table columns Timestamp/Location/Serial/Tran/Vert/Long/PVS/
  Mic/Flags; rows open the shared event-detail modal (Chart.js + event-modal.js
  come from the modal partial). Lazy-loads on first open; refreshes on
  sfm-event-review-saved.
- Last event per location card: thread last_event (already in
  events_for_location stats) through the locations endpoint and show
  "Last event: …" on vibration cards.

Reuses the same event source + modal as the per-location Events tab.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

templates/partials/projects/location_list.html

@@ -74,6 +74,9 @@
                                 {% else %}
                                     <span class="italic text-gray-400 dark:text-gray-500">No active assignment</span>
                                 {% endif %}
+                                {% if item.last_event %}
+                                    <span>Last event: <span class="text-gray-700 dark:text-gray-300">{{ item.last_event[:16] }}</span></span>
+                                {% endif %}
                             </div>
                         </div>
                     </div>