fix: deployment capture coords now reach existing locations

The /deploy classify "Assign to existing location" path dropped the captured
GPS — only "Create new location" applied it — so units assigned to pre-existing
coordless locations left those locations without a pin.

- Classify (promote) now backfills the captured GPS onto an existing location
  that has no coordinates (doesn't clobber operator-set coords).
- Add "Reforward info" button on Assigned deployment cards + endpoint
  POST /pending/{id}/resync-location that re-pushes a capture's GPS onto its
  assigned location (explicit action, overwrites). Fixes already-classified
  locations and guards against this recurring. Logged to unit history.

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

templates/admin/pending_deployments.html

@@ -207,9 +207,19 @@ function _renderPdCard(pd) {
             </button>
         </div>`;
     } else if (pd.status === 'assigned') {
+        const reforward = pd.coordinates
+            ? `<button onclick="reforwardInfo('${_esc(pd.id)}')"
+                    class="mt-2 inline-flex items-center gap-1.5 px-3 py-1.5 text-xs rounded-lg border border-seismo-orange/40 bg-seismo-orange/10 text-seismo-orange hover:bg-seismo-orange/20 transition-colors"
+                    title="Re-push this capture's GPS coordinates onto its assigned location">
+                    <svg class="w-3.5 h-3.5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                        <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M4 4v5h.582m15.356 2A8.001 8.001 0 004.582 9m0 0H9m11 11v-5h-.581m0 0a8.003 8.003 0 01-15.357-2m15.357 2H15"></path>
+                    </svg>
+                    Reforward info
+                </button>`
+            : '';
         footerActions = `<div class="mt-3 text-xs text-green-700 dark:text-green-400">
             Promoted ${_fmtDateTime(pd.promoted_at)} → assignment <span class="font-mono">${_esc((pd.resulting_assignment_id || '').slice(0, 8))}…</span>
-        </div>`;
+        </div>${reforward}`;
     } else if (pd.status === 'cancelled') {
         footerActions = `<div class="mt-3 text-xs text-gray-500 dark:text-gray-400">
             Cancelled ${_fmtDateTime(pd.cancelled_at)}${pd.cancelled_reason ? ` — ${_esc(pd.cancelled_reason)}` : ''}
@@ -459,6 +469,22 @@ async function cancelPending(pendingId) {
     }
 }
 
+// Re-push a promoted capture's GPS coordinates onto its assigned location.
+async function reforwardInfo(pendingId) {
+    try {
+        const r = await fetch(`/api/deployments/pending/${pendingId}/resync-location`, {
+            method: 'POST',
+        });
+        const j = await r.json().catch(() => ({}));
+        if (!r.ok) throw new Error(j.detail || 'HTTP ' + r.status);
+        const msg = `Coordinates synced to "${j.location_name}": ${j.coordinates}`;
+        if (window.showToast) showToast(msg, 'success'); else alert(msg);
+    } catch (e) {
+        const msg = 'Reforward failed: ' + e.message;
+        if (window.showToast) showToast(msg, 'error'); else alert(msg);
+    }
+}
+
 // Kick off the initial load.
 loadPdList();
 // Refresh awaiting count every 30s for the badge.