release: v4.8.12 chat notification & file-transfer UI fixes

fix(file-transfer): announce received file once, not many times

The per-transfer lock used a single `if` check, so when 3+ chunk
operations queued on the same fileId they awaited the same in-flight
lock and then ran concurrently, breaking assembly atomicity. The lock
now loops until the slot is free (true serialization) and file assembly
is idempotent, so `File received` shows exactly once per file.

fix(verification): stop duplicate connection-setup system messages

handleVerificationBothConfirmed had no guard, so when both peers sent
verification_both_confirmed symmetrically one side ran both the local
detection path and the peer-notification path, emitting "Both parties
confirmed!" and the verified transition (and "Secure connection
established") twice. It now bails out if both confirmations are already
recorded.

fix(ui): wrap long DTLS fingerprint inside the chat bubble

The message text column is a flex child with default min-width:auto, so
the long unbroken fingerprint overflowed. Added min-w-0 so break-words
can wrap it.

chore(release): bump version to 4.8.12 in header, init banner, manifest

dist/app-boot.js

@@ -4340,18 +4340,20 @@ var AtomicOperations = class {
     this.locks = /* @__PURE__ */ new Map();
   }
   async withLock(key, operation) {
-    if (this.locks.has(key)) {
+    while (this.locks.has(key)) {
       await this.locks.get(key);
     }
-    const lockPromise = (async () => {
-      try {
-        return await operation();
-      } finally {
-        this.locks.delete(key);
-      }
-    })();
+    let releaseLock;
+    const lockPromise = new Promise((resolve) => {
+      releaseLock = resolve;
+    });
     this.locks.set(key, lockPromise);
-    return lockPromise;
+    try {
+      return await operation();
+    } finally {
+      this.locks.delete(key);
+      releaseLock();
+    }
   }
 };
 var RateLimiter = class {
@@ -5297,6 +5299,10 @@ var EnhancedSecureFileTransfer = class {
     return true;
   }
   async assembleFile(receivingState) {
+    if (receivingState._assembled) {
+      return;
+    }
+    receivingState._assembled = true;
     try {
       receivingState.status = "assembling";
       for (let i = 0; i < receivingState.totalChunks; i++) {
@@ -14873,6 +14879,9 @@ var EnhancedSecureWebRTCManager = class _EnhancedSecureWebRTCManager {
     this._checkBothVerificationsConfirmed();
   }
   handleVerificationBothConfirmed(data) {
+    if (this.bothVerificationsConfirmed) {
+      return;
+    }
     this.bothVerificationsConfirmed = true;
     if (this.onVerificationStateChange) {
       this.onVerificationStateChange({
@@ -17493,7 +17502,7 @@ Right-click or Ctrl+click to disconnect`,
             React.createElement("p", {
               key: "subtitle",
               className: "text-xs sm:text-sm text-muted hidden sm:block"
-            }, "End-to-end freedom v4.8.10")
+            }, "End-to-end freedom v4.8.12")
           ])
         ]),
         // Status and Controls - Responsive

dist/app.js

@@ -414,7 +414,7 @@ var EnhancedChatMessage = ({ message, type, timestamp }) => {
       }),
       React.createElement("div", {
         key: "text",
-        className: "flex-1"
+        className: "flex-1 min-w-0"
       }, [
         React.createElement("div", {
           key: "message",
@@ -1987,7 +1987,7 @@ var EnhancedSecureP2PChat = () => {
       } catch (error) {
       }
     }
-    handleMessage(" SecureBit.chat Enhanced Security Edition v4.8.10 - ECDH + DTLS + SAS initialized. Ready to establish a secure connection with ECDH key exchange, DTLS fingerprint verification, and SAS authentication to prevent MITM attacks.", "system");
+    handleMessage(" SecureBit.chat Enhanced Security Edition v4.8.12 - ECDH + DTLS + SAS initialized. Ready to establish a secure connection with ECDH key exchange, DTLS fingerprint verification, and SAS authentication to prevent MITM attacks.", "system");
     const handleBeforeUnload = (event) => {
       if (event.type === "beforeunload" && !isTabSwitching) {
         if (webrtcManagerRef.current && webrtcManagerRef.current.isConnected()) {