fix: pass kebab menu data through a temporary file

[cookerpapa]

Fixes #111.

The kebab popup currently puts its full action list in the command line. This is the long-argument launch path identified in the report about menus being terminated on repeated opens.

Pass { paneName, actions } through the existing popup temporary-data mechanism and read that file in the popup entry point. Menu positioning, selection and result handling stay the same. The shared launcher removes the file on selection, cancellation and launch failure.

Add regression coverage for the manager-to-file path, cleanup and the entry point's file loading/error handling. Update the existing anchor test for the new data argument and the already-current 26-row height limit.

Validation:

• TypeScript compilation and the runtime-parity guard pass.
• A real compiled popup in a PTY loads a 5,517-byte data file, accepts the close shortcut, writes the correct result and exits with status 0.
• The two focused Vitest files report all 7 cases passing, but the local worker pool hangs before the final report and times out. This runner problem also occurs on unchanged dmux tests; a completed suite run is still needed.
• The reported macOS endpoint-security environment has not been reproduced here.