fix(desktop): shorten darwin pty helper path

[LeonSGP43]

Summary

• stage a second darwin spawn-helper copy under dist/bin during desktop packaging
• patch the staged node-pty unixTerminal.js to prefer that shorter helper path on macOS
• verify the packaging contract with focused staging tests and desktop bundle assertions

Verification

• node --test apps/desktop/scripts/stage-native-deps.test.mjs
• node --check apps/desktop/scripts/stage-native-deps.mjs
• node --check apps/desktop/scripts/stage-native-deps.test.mjs
• node --check apps/desktop/scripts/test-desktop.mjs
• git diff --check

Closes #62429

[teknium1]

Thanks for the focused macOS packaging fix. Current main still resolves node-pty’s helper from its nested native directory (node_modules/node-pty/lib/unixTerminal.js:29-32), while the desktop staging path remains under dist/node_modules/node-pty (apps/desktop/scripts/stage-native-deps.mjs:82-118). The proposed dist/bin/spawn-helper fallback is included by the existing dist/** package and unpack rules (apps/desktop/package.json:170-195), and the PR adds both staging and packaged-bundle assertions.

No verified problems found in the diff. This is an automated hermes-sweeper review.