fix(frontend): issues from the 10-25 Chrome sweep

- Incident detail "← Incidents" used router.back(), so arriving from Live
  or a shared link it went to the map / out of the app. Now a Link.
- Resolved incidents showed "0m elapsed" (manual resolve sets no
  resolved_at, updated_at can predate the last call): end is now the
  latest of resolved_at, updated_at and the newest call.
- Admin: the max-width toggle wrapped the tab bar, so it reflowed on every
  tab switch and left the cursor over e.g. "Close calls". Body only now.
- STT Eval sat on "Loading…" forever when a scanned page had zero matches
  but a next_cursor — the refill effect didn't depend on cursor.
- Trip event blocks used dark-only bg-indigo-950/60: unreadable in light
  mode. Theme tokens now.
- Reassign modal said "connected for the first time" on configured nodes.
- Dark-mode placeholders dimmed + italic; they read as filled-in values.

Frontend unverified locally (no Node, #207); CI build typechecks.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

drb-frontend/app/incidents/[id]/page.tsx

@@ -2,7 +2,8 @@
 
 import dynamic from "next/dynamic";
 import { useMemo, useState } from "react";
-import { useParams, useRouter } from "next/navigation";
+import Link from "next/link";
+import { useParams } from "next/navigation";
 import { useIncident } from "@/lib/useIncidents";
 import { useCallsByIncident } from "@/lib/useCalls";
 import { useAuth } from "@/components/AuthProvider";
@@ -21,9 +22,9 @@ const MapView = dynamic(() => import("@/components/MapView"), { ssr: false });
 
 const EARLIER_PAGE_SIZE = 8;
 
-function elapsedLabel(startedAt: string, active: boolean, updatedAt: string): string {
+function elapsedLabel(startedAt: string, active: boolean, endedAt: string): string {
   const start = new Date(startedAt).getTime();
-  const end = active ? Date.now() : new Date(updatedAt).getTime();
+  const end = active ? Date.now() : new Date(endedAt).getTime();
   const mins = Math.max(0, Math.round((end - start) / 60000));
   if (mins < 60) return `${mins}m`;
   const hrs = Math.floor(mins / 60);
@@ -33,7 +34,6 @@ function elapsedLabel(startedAt: string, active: boolean, updatedAt: string): st
 export default function IncidentDetailPage() {
   const params = useParams();
   const id = params.id as string;
-  const router = useRouter();
 
   const { incident, loading } = useIncident(id);
   const { calls, loading: callsLoading } = useCallsByIncident(id);
@@ -82,18 +82,23 @@ export default function IncidentDetailPage() {
   const unitsCleared = incident.units_cleared ?? [];
   const vehicles = incident.vehicles ?? [];
   const active = incident.status === "active";
+  // A manual resolve doesn't set resolved_at and updated_at can predate the
+  // last call, which showed "0m elapsed" on an 11-call incident — so a
+  // resolved incident runs to the latest of those and its newest call.
+  const resolvedEnd = [incident.resolved_at, incident.updated_at, newestFirst[0]?.ended_at, newestFirst[0]?.started_at]
+    .filter((t): t is string => !!t)
+    .reduce((a, b) => (b > a ? b : a), incident.started_at);
 
   const visible = newestFirst.slice(0, earlierShown);
   const remaining = newestFirst.length - visible.length;
 
   return (
     <div className="space-y-4">
-      <button
-        onClick={() => router.back()}
-        className="text-xs text-ink-muted hover:text-ink-2 transition-colors"
-      >
+      {/* A real link, not router.back(): arriving from Live or a shared URL,
+          "back" went to the map or out of the app. */}
+      <Link href="/incidents" className="text-xs text-ink-muted hover:text-ink-2 transition-colors">
         ← Incidents
-      </button>
+      </Link>
 
       {/* Header — glyph, severity chip, status, title at 27px, elapsed/path/count */}
       <div className="flex flex-col sm:flex-row sm:items-start sm:justify-between gap-3">
@@ -109,7 +114,7 @@ export default function IncidentDetailPage() {
             {incident.title ?? "Incident"}
           </h1>
           <p className="text-xs text-ink-muted font-mono">
-            {elapsedLabel(incident.started_at, active, incident.updated_at)} elapsed
+            {elapsedLabel(incident.started_at, active, resolvedEnd)} elapsed
             {path?.movement && path.lengthKm > 0 && <> · {path.lengthKm.toFixed(1)} km path</>}
             {path?.mayBeMerged && (
               <span title={`The calls' locations span ${path.lengthKm.toFixed(0)} km (over ${MAY_BE_MERGED_KM} km) — this may be more than one event`}>