feat: add terminal broadcast, context menu, and shell close

Complete multi-pane broadcast, standard terminal right-click actions, batch host selection with progress, and native ssh_close_shell so closing a pane tears down the remote shell.

Co-authored-by: Cursor <cursoragent@cursor.com>

test/utils/terminalPanes.test.ts

@@ -1,5 +1,8 @@
 import { describe, expect, it } from 'vitest'
-import { resolveTerminalInputTargets } from '../../src/utils/terminalPanes'
+import {
+  resolveTerminalInputTargets,
+  shouldBroadcastTerminalInput,
+} from '../../src/utils/terminalPanes'
 
 const panes = [
   { id: 'left', shellId: 'shell-1' },
@@ -23,4 +26,11 @@ describe('terminal pane input routing', () => {
     expect(resolveTerminalInputTargets(panes, 'starting', false)).toEqual([])
     expect(resolveTerminalInputTargets(panes, 'missing', false)).toEqual([])
   })
+
+  it('never broadcasts input originating from a local terminal', () => {
+    expect(shouldBroadcastTerminalInput(true, true, 'local')).toBe(false)
+    expect(shouldBroadcastTerminalInput(true, true, 'ssh-connection')).toBe(false)
+    expect(shouldBroadcastTerminalInput(true, false, 'ssh-connection')).toBe(true)
+    expect(shouldBroadcastTerminalInput(true, false, null)).toBe(false)
+  })
 })