Add relay status badge, toast notifications, per-tab feed timestamps, relay UX improvements

- Relay status badge in feed header: shows connected/total relay count with
  color coding (green >75%, yellow 25-75%, red <25%), hover tooltip with
  per-relay status
- Toast notification system: transient messages for connection lost,
  reconnecting, relay reset, and back-online events
- Per-tab "last updated" relative timestamp in feed header (global,
  following, trending tracked independently)
- Consolidated all relay management into RelaysView (removed duplicate
  relay section from Settings); per-relay remove button on health cards
- Show all supported NIP badges on relay cards (was filtering to 11 notable)
- Tooltips on relay status dots explaining green/yellow/red/gray meaning
- Fix relay removal with trailing-slash URL normalization
- Fix stale health results lingering after relay removal
- Add acknowledgements section to README

src/components/shared/SettingsView.tsx

@@ -4,7 +4,7 @@ import { writeTextFile } from "@tauri-apps/plugin-fs";
 import { useUserStore } from "../../stores/user";
 import { useMuteStore } from "../../stores/mute";
 import { useBookmarkStore } from "../../stores/bookmark";
-import { getNDK, getStoredRelayUrls, addRelay, removeRelay, publishRelayList } from "../../lib/nostr";
+import { getStoredRelayUrls } from "../../lib/nostr";
 import { useProfile } from "../../hooks/useProfile";
 import { NWCWizard } from "./NWCWizard";
 import { getNotificationSettings, saveNotificationSettings, ensurePermission } from "../../lib/notifications";
@@ -113,117 +113,6 @@ function MutedKeywordsSection() {
   );
 }
 
-function RelayRow({ url, onRemove }: { url: string; onRemove: () => void }) {
-  const ndk = getNDK();
-  const relay = ndk.pool?.relays.get(url);
-  const connected = relay?.connected ?? false;
-
-  return (
-    <div className="flex items-center gap-3 px-3 py-2 border border-border text-[12px] group">
-      <span className={`w-1.5 h-1.5 rounded-full shrink-0 ${connected ? "bg-success" : "bg-text-dim"}`} />
-      <span className="text-text truncate flex-1 font-mono">{url}</span>
-      <button
-        onClick={onRemove}
-        className="text-text-dim hover:text-danger text-[10px] opacity-0 group-hover:opacity-100 transition-opacity shrink-0"
-      >
-        remove
-      </button>
-    </div>
-  );
-}
-
-function RelaySection() {
-  const { loggedIn } = useUserStore();
-  const [relays, setRelays] = useState<string[]>(() => getStoredRelayUrls());
-  const [input, setInput] = useState("");
-  const [error, setError] = useState<string | null>(null);
-  const [publishing, setPublishing] = useState(false);
-  const [publishedAt, setPublishedAt] = useState<number | null>(null);
-
-  const handleAdd = () => {
-    const url = input.trim();
-    if (!url) return;
-    if (!url.startsWith("ws://") && !url.startsWith("wss://")) {
-      setError("URL must start with ws:// or wss://");
-      return;
-    }
-    if (relays.includes(url)) {
-      setError("Already in list");
-      return;
-    }
-    addRelay(url);
-    setRelays(getStoredRelayUrls());
-    setInput("");
-    setError(null);
-  };
-
-  const handleRemove = (url: string) => {
-    removeRelay(url);
-    setRelays(getStoredRelayUrls());
-  };
-
-  const handleKeyDown = (e: React.KeyboardEvent) => {
-    if (e.key === "Enter") handleAdd();
-    if (e.key === "Escape") setInput("");
-  };
-
-  const handlePublishRelayList = async () => {
-    setPublishing(true);
-    try {
-      await publishRelayList(getStoredRelayUrls());
-      setPublishedAt(Date.now());
-    } catch {
-      // ignore — publishing failure is non-critical
-    } finally {
-      setPublishing(false);
-    }
-  };
-
-  return (
-    <section>
-      <h2 className="text-text text-[11px] font-medium uppercase tracking-widest mb-2 text-text-dim">Relays</h2>
-      <div className="space-y-1 mb-3">
-        {relays.length === 0 && (
-          <p className="text-text-dim text-[12px] px-1">No relays configured.</p>
-        )}
-        {relays.map((url) => (
-          <RelayRow key={url} url={url} onRemove={() => handleRemove(url)} />
-        ))}
-      </div>
-      <div className="flex gap-2">
-        <input
-          value={input}
-          onChange={(e) => { setInput(e.target.value); setError(null); }}
-          onKeyDown={handleKeyDown}
-          placeholder="wss://relay.example.com"
-          className="flex-1 bg-bg border border-border px-3 py-1.5 text-text text-[12px] font-mono focus:outline-none focus:border-accent/50 placeholder:text-text-dim"
-        />
-        <button
-          onClick={handleAdd}
-          className="px-3 py-1.5 text-[11px] border border-border text-text-muted hover:text-accent hover:border-accent/40 transition-colors shrink-0"
-        >
-          add
-        </button>
-      </div>
-      {error && <p className="text-danger text-[11px] mt-1">{error}</p>}
-      {loggedIn && !!getNDK().signer && (
-        <div className="mt-3">
-          <button
-            onClick={handlePublishRelayList}
-            disabled={publishing}
-            className="text-[11px] px-3 py-1.5 border border-border text-text-muted hover:text-accent hover:border-accent/40 transition-colors disabled:opacity-40 disabled:cursor-not-allowed"
-          >
-            {publishing ? "publishing…" : publishedAt ? "published ✓" : "publish relay list to Nostr"}
-          </button>
-          <p className="text-text-dim text-[10px] mt-1">
-            Saves your relay list as a kind 10002 event (NIP-65) so other clients can find your notes.
-          </p>
-        </div>
-      )}
-    </section>
-  );
-}
-
 function IdentitySection() {
   const { npub, loggedIn } = useUserStore();
   const [copied, setCopied] = useState(false);
@@ -391,7 +280,6 @@ export function SettingsView() {
       <div className="flex-1 overflow-y-auto p-4 space-y-8">
         <WalletSection />
         <NotificationSection />
-        <RelaySection />
         <ExportSection />
         <IdentitySection />
         <MuteSection />