fix(terminal): keep home input after an attached popup closes

Attach close preparation clears the popup session ref, then unmount
cleanup called closeSession. That emits netcatty:exit to the home
renderer and can kill the shared PTY. Skip that second close.

Co-authored-by: 陈大猫 <binaricat@users.noreply.github.com>

components/Terminal.tsx

@@ -1794,6 +1794,14 @@ const TerminalComponent: React.FC<TerminalProps> = ({
 
     if (!closingSessionId) {
       disposeSessionListeners();
+      // Close preparation already cleared sessionRef after the display handoff.
+      // Unmount teardown calls cleanup again. An attach popup must not
+      // closeSession on that second pass: worker mode emits netcatty:exit to
+      // the home renderer before the boot-epoch check, which drops home input
+      // (sessionRef = null) while a mismatched epoch leaves the PTY alive.
+      if (attachExistingSession) {
+        return;
+      }
       // Still notify main so in-flight SSH passphrase prompts for this UI
       // sessionId are aborted even before a backend session was attached.
       try {

components/terminal/TerminalView.test.tsx

@@ -652,6 +652,16 @@ test("terminal boot is cancelable and closes eagerly on cleanup", () => {
   );
   // Owner panes close the pending backend; attach popups only dispose xterm.
   assert.match(neverConnectedBranch, /if \(!attachExistingSession\)/);
+  const emptySessionBranch = readFileSync(new URL("../Terminal.tsx", import.meta.url), "utf8");
+  const emptyStart = emptySessionBranch.indexOf("if (!closingSessionId)");
+  const emptyEnd = emptySessionBranch.indexOf("Observe/attach popups must not kill", emptyStart);
+  const emptyBranch = emptySessionBranch.slice(emptyStart, emptyEnd);
+  const attachGuardAt = emptyBranch.indexOf("if (attachExistingSession)");
+  const emptyCloseAt = emptyBranch.indexOf("terminalBackend.closeSession(");
+  assert.ok(
+    attachGuardAt !== -1 && emptyCloseAt !== -1 && attachGuardAt < emptyCloseAt,
+    "a second attach cleanup after sessionRef is cleared must not closeSession",
+  );
   assert.match(effectsSource, /let ownedRuntime:/);
   assert.match(
     cleanup,