feat: add saved messages, public chat discovery/join, and chat delete options

- add Saved Messages system chat with dedicated API

- add public group/channel metadata and discover/join endpoints

- add chat delete flow with for_all option and channel-wide delete

- switch message actions to context menu and improve reply/forward visuals

- improve microphone permission handling for voice recording

web/src/components/MessageComposer.tsx

@@ -168,6 +168,13 @@ export function MessageComposer() {
 
   async function startRecord() {
     try {
+      if (navigator.permissions && navigator.permissions.query) {
+        const permission = await navigator.permissions.query({ name: "microphone" as PermissionName });
+        if (permission.state === "denied") {
+          setUploadError("Microphone access denied. Allow microphone in browser site permissions.");
+          return;
+        }
+      }
       const stream = await navigator.mediaDevices.getUserMedia({ audio: true });
       const recorder = new MediaRecorder(stream);
       chunksRef.current = [];
@@ -182,7 +189,7 @@ export function MessageComposer() {
       recorder.start();
       setIsRecording(true);
     } catch {
-      setUploadError("Microphone access denied.");
+      setUploadError("Microphone access denied. Please allow microphone and retry.");
     }
   }