feat: live status chip on NRL list cards

Add a compact live-status chip to each NRL card in the location list, so the
inline list next to the map (Overview tab) and the Sound > NRLs tab show live
state alongside the new live tiles. Both surfaces share location_list.html, so
this lands in both.

- Chip shows "● <Leq> dB" when measuring (tinted green/amber/red at the same
  55/70 thresholds as the live tiles), else Stopped / Offline / Wedged.
  Hidden for cards with no assigned unit and for vibration locations.
- Painted by the existing 15s Overview poller (no extra requests). Repaints on
  htmx:afterSwap so the chips survive the NRL list reloading (e.g. the 30s
  dashboard swap).

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

templates/partials/projects/location_list.html

@@ -78,8 +78,12 @@
                         </div>
                     </div>
 
-                    <!-- Right column: small assign/unassign pill + 3-dot menu -->
+                    <!-- Right column: live status chip + small assign/unassign pill + 3-dot menu -->
                     <div class="flex items-center gap-2 shrink-0">
+                        <!-- Live status chip — painted by the Overview live poller
+                             (paintInlineLive) keyed on data-loc-live. Hidden until
+                             there's live data for this location. -->
+                        <span class="nrl-live-chip hidden" data-loc-live="{{ item.location.id }}"></span>
                         {% if not item.assignment %}
                             <!-- Primary action: visible because the unassigned card
                                  is most likely getting clicked on right after creation -->