feat: paginate closed streams tab (#148)

Closed streams grow unbounded as teams age and can reach 1000s of items,
while open streams stay bounded by active work. Switch the streams list
to subscribe per-status so each tab only pulls what it renders, and cap
the closed tab to a 50-item window that grows via a Load more action.

The open tab remains unbounded so per-row realtime features — autoplay,
huddle indicators — keep full coverage of the streams that matter.
Closed streams are archived and don't need push behavior, which side-
steps the autoplay baseline-reset and huddle-on-page-2 risks that made
pagination complicated for the open tab.

Refs flowy-live/llink#138.

Co-authored-by: Claude <[email protected]>

js/src/lib/firestore-particles.ts

@@ -161,6 +161,8 @@ export interface SubscribeToParticleChildrenOptions {
   onAdded?: (child: Particle) => void;
   onRemoved?: (child: Particle, updatedChildren: Particle[]) => void;
   whereFilter?: QueryFieldFilterConstraint;
+  /** Optional cap on results. Applied after order/where constraints. */
+  limit?: number;
 }
 
 export function subscribeToParticleChildren(
@@ -174,6 +176,7 @@ export function subscribeToParticleChildren(
     onAdded,
     onRemoved,
     whereFilter,
+    limit: limitValue,
   }: SubscribeToParticleChildrenOptions
 ): Unsubscribe {
   let q = query(typedCollection(collectionPath), orderBy(orderByField, orderDirection));
@@ -186,6 +189,9 @@ export function subscribeToParticleChildren(
   if (whereFilter) {
     q = query(q, whereFilter);
   }
+  if (limitValue !== undefined) {
+    q = query(q, limit(limitValue));
+  }
   return onSnapshot(
     q,
     (snap) => {