fix(terminal): reset kitty mirror on fresh spawn to cover replaced-PTY late exits

The exit handler resets the per-pane kitty keyboard mirror, but a late exit
from a replaced PTY takes the stale-transport early return and skips it —
so a restart-in-place could leak the old TUI's kitty flags into the fresh
shell, kitty-encoding Option chords the shell cannot parse. A fresh spawn
is by definition a new process with kitty state at zero, so startFreshSpawn
now resets the reused tracker itself, alongside the other per-pane mode
state it already clears. Reattach paths are untouched, so a live TUI's
mirrored flags still survive reconnects.

src/renderer/src/components/terminal-pane/pty-connection.test.ts

@@ -920,6 +920,32 @@ describe('connectPanePty', () => {
     )
   })
 
+  // Why: a late exit from a replaced PTY takes the stale-transport early
+  // return in onExit and skips the kitty mirror reset there — a fresh spawn
+  // must therefore reset the reused per-pane tracker itself, or a
+  // restart-in-place leaks the old TUI's kitty flags into a fresh shell.
+  it('resets a stale kitty keyboard mirror when spawning a fresh PTY', async () => {
+    const { connectPanePty } = await import('./pty-connection')
+    const { TerminalKittyKeyboardModeTracker } =
+      await import('../../../../shared/terminal-kitty-keyboard-mode-tracker')
+    const transport = createMockTransport()
+    transportFactoryQueue.push(transport)
+    const staleTracker = new TerminalKittyKeyboardModeTracker()
+    staleTracker.scan('\x1b[>1u')
+    expect(staleTracker.flags).toBe(1)
+    // Why: a unique tab id keeps this pane's key clear of pendingSpawnByPaneKey
+    // entries from other tests, so the connect deterministically fresh-spawns.
+    const deps = createDeps({
+      tabId: 'tab-kitty-fresh-spawn',
+      paneKittyKeyboardModesRef: { current: new Map([[91, staleTracker]]) }
+    })
+
+    connectPanePty(createPane(91) as never, createManager(91) as never, deps as never)
+    await flushAsyncTicks()
+
+    expect(staleTracker.flags).toBe(0)
+  })
+
   it('threads the resolved local project runtime into IPC terminal transport options', async () => {
     const { connectPanePty } = await import('./pty-connection')
     const transport = createMockTransport()

src/renderer/src/components/terminal-pane/pty-connection.ts

@@ -3771,6 +3771,11 @@ export function connectPanePty(
     ): void => {
       clearPaneMode2031State()
       clearHiddenOutputRestoreState()
+      // Why: a fresh spawn is a new process with kitty keyboard flags at
+      // zero. The exit-handler reset alone is not enough: a late exit from a
+      // replaced PTY takes the stale-transport early return and skips it, so
+      // a restart-in-place would leak the old TUI's flags into a fresh shell.
+      kittyKeyboardModes.reset()
       prepareFreshShellViewportForSpawn(options)
       if (connectionId && startupOverride?.command) {
         // Why: SSH providers use `command` only as spawn metadata; the renderer