Add optional INDI mount control

[hjoungjoo]

Summary

• add optional INDI mount-control process and menu settings
• add object-detail actions for INDI mount control
• add installation notes and keyboard mapping docs for INDI usage

Context

This is split out from the larger MF PiFinder compatibility branch as a focused draft PR. INDI support is optional and remains disabled unless configured.

Testing

• python3 -m py_compile python/PiFinder/main.py python/PiFinder/mountcontrol_indi.py python/PiFinder/ui/callbacks.py python/PiFinder/ui/menu_structure.py python/PiFinder/ui/object_details.py
• git diff --check upstream/main...HEAD

Notes

• tested on the MF PiFinder branch with optional INDI install flow
• keeping this as Draft while hardware and maintainer review continue