Stop opening duplicate WebSocket connections

The real problem: nostr.relay() and nostr.group() each open brand new
WebSocket connections outside the pool. Every hook that called these
was creating duplicate connections to relays the pool already had open.

Fixed by routing all queries and subscriptions through the pool (nostr)
directly, which reuses its internal connections:

- useStreamPosts: nostr.relay('wss://relay.ditto.pub') → nostr
- useStreamKind: nostr.relay('wss://relay.ditto.pub') → nostr
- useSearchProfiles: nostr.relay('wss://relay.ditto.pub') → nostr
- useFollowActions: nostr.group([...]) → nostr
- FollowPackDetailContent: nostr.group([...]) → nostr

Also reverted the hacky relay cleanup code in NostrProvider since
it was trying to solve the wrong problem.

Co-authored-by: shakespeare.diy <assistant@shakespeare.diy>

src/hooks/useStreamPosts.ts

@@ -95,8 +95,6 @@ export function useStreamPosts(query: string, options: StreamPostsOptions) {
       setAllEvents(Array.from(eventMap.values()).sort((a, b) => b.created_at - a.created_at));
     }
 
-    const relay = nostr.relay('wss://relay.ditto.pub');
-
     // Build the kinds list: either vines-only or kind 1 + enabled extras
     const kinds: number[] = isVines
       ? [34236]
@@ -108,10 +106,10 @@ export function useStreamPosts(query: string, options: StreamPostsOptions) {
       baseFilter.search = query.trim();
     }
 
-    // 1. Fetch initial batch
+    // 1. Fetch initial batch (uses pool, reuses existing connections)
     (async () => {
       try {
-        const events = await relay.query(
+        const events = await nostr.query(
           [{ ...baseFilter, limit: 40 }],
           { signal: ac.signal },
         );
@@ -124,11 +122,11 @@ export function useStreamPosts(query: string, options: StreamPostsOptions) {
       if (alive) setIsLoading(false);
     })();
 
-    // 2. Stream new events
+    // 2. Stream new events (uses pool, reuses existing connections)
     (async () => {
       try {
         const now = Math.floor(Date.now() / 1000);
-        for await (const msg of relay.req(
+        for await (const msg of nostr.req(
           [{ ...baseFilter, since: now, limit: 100 }],
           { signal: ac.signal },
         )) {