frontend: date range picker on Incidents and Archive; fix Archive paging

Incidents and Archive get a from/to date range (native date inputs,
local-day bounds). Incidents filters in the Firestore query; Archive
passes date_from/date_to to GET /calls/search, which applies them as a
started_at range — both ride the existing org_id/started_at index.

Also fixes /calls/search and /calls/eval-queue paging: the cursor went to
Firestore as a raw ISO string against a timestamp field, which compares
by type rather than time, so "Load more" re-read the first page. Cursor
and range bounds are now parsed to datetimes (400 on garbage).

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

drb-frontend/lib/useIncidents.ts

@@ -11,7 +11,7 @@ const toISO = (v: unknown): string =>
   (v as { toDate?: () => Date })?.toDate?.()?.toISOString?.() ??
   (typeof v === "string" ? v : new Date().toISOString());
 
-export function useIncidents(limitCount = 100) {
+export function useIncidents(limitCount = 100, dateFrom?: Date, dateTo?: Date) {
   const [incidents, setIncidents] = useState<IncidentRecord[]>([]);
   const [loading, setLoading] = useState(true);
   const [error, setError] = useState<string | null>(null);
@@ -20,6 +20,10 @@ export function useIncidents(limitCount = 100) {
   const [hasMore, setHasMore] = useState(false);
   const { orgId } = useAuth();
 
+  // Stable ms values so the effect dependency doesn't fire on every render
+  const dateFromMs = dateFrom?.getTime();
+  const dateToMs = dateTo?.getTime();
+
   useEffect(() => {
     let unsubFirestore: (() => void) | undefined;
 
@@ -37,9 +41,12 @@ export function useIncidents(limitCount = 100) {
         return;
       }
 
+      // A range on the ordered field rides the existing org_id/started_at index.
       const q = query(
         collection(db, "incidents"),
         where("org_id", "==", orgId),
+        ...(dateFromMs != null ? [where("started_at", ">=", new Date(dateFromMs))] : []),
+        ...(dateToMs != null ? [where("started_at", "<=", new Date(dateToMs))] : []),
         orderBy("started_at", "desc"),
         limit(limitCount)
       );
@@ -65,7 +72,7 @@ export function useIncidents(limitCount = 100) {
       unsubAuth();
       if (unsubFirestore) unsubFirestore();
     };
-  }, [limitCount, orgId]);
+  }, [limitCount, dateFromMs, dateToMs, orgId]);
 
   return { incidents, loading, error, hasMore };
 }