fix: use _term.paste() for Ctrl+Shift+V — enables bracketed paste mode

Raw WebSocket send bypassed xterm.js's paste pipeline, so multiline
text was sent without bracketed paste markers (ESC[200~...ESC[201~).
The shell treated each newline as Enter, executing lines separately.
Fix: _term.paste(text) goes through the proper pipeline — converts
CR/LF, wraps in bracketed paste markers, then fires onData → WebSocket.

muxplex/frontend/terminal.js

@@ -375,8 +375,12 @@ function openTerminal(sessionName, remoteId) {
       e.preventDefault();  // suppress browser native paste event (prevents double-paste via xterm textarea)
       if (navigator.clipboard && navigator.clipboard.readText) {
         navigator.clipboard.readText().then(function(text) {
-          if (text && _ws && _ws.readyState === WebSocket.OPEN) {
-            _ws.send(_encodePayload(0x30, text));
+          if (text && _term) {
+            // Use xterm.js paste() pipeline: converts \r\n→\r, wraps in bracketed
+            // paste markers (ESC[200~...ESC[201~) so the shell treats multiline text
+            // as a paste block rather than executing each line on Enter.
+            // Fires onData → our WebSocket handler automatically.
+            _term.paste(text);
           }
         }).catch(function() {});
       }

muxplex/frontend/tests/test_terminal.mjs

@@ -1012,6 +1012,33 @@ test('terminal.js Ctrl+Shift+V handler calls preventDefault to suppress double p
   );
 });
 
+// --- Multiline paste (bracketed paste mode) ---
+
+test('terminal.js Ctrl+Shift+V uses _term.paste() for bracketed paste mode', () => {
+  // Regression: the handler sent raw bytes via _ws.send(_encodePayload(0x30, text)),
+  // bypassing xterm.js's paste pipeline. Multiline text had no bracketed paste markers
+  // (ESC[200~...ESC[201~), so the shell treated each \n as Enter — executing each line
+  // separately instead of pasting as a block.
+  // Fix: use _term.paste(text) which goes through the proper pipeline.
+  const source = fs.readFileSync(new URL('../terminal.js', import.meta.url), 'utf8');
+
+  // Locate the Ctrl+Shift+V block
+  const vIdx = source.indexOf("e.key === 'V'");
+  assert.ok(vIdx !== -1, "must have a Ctrl+Shift+V key check");
+  const blockStart = source.lastIndexOf('if (', vIdx);
+  const blockEnd = source.indexOf('return false', vIdx);
+  const vBlock = source.substring(blockStart, blockEnd);
+
+  assert.ok(
+    vBlock.includes('_term.paste'),
+    'Ctrl+Shift+V must use _term.paste() for proper bracketed paste mode support',
+  );
+  assert.ok(
+    !vBlock.includes('_encodePayload') && !vBlock.includes('_ws.send'),
+    'Ctrl+Shift+V must NOT send raw bytes via WebSocket (bypasses bracketed paste wrapping)',
+  );
+});
+
 // --- Federation reconnect routing ---
 
 test('terminal.js reconnect uses federation connect path for remote sessions', () => {