[codex] Connect IQ and UI revamp

[Shruichan]

Summary

• removes generated virtualenv/package artifacts from git tracking and expands ignore rules
• adds Connect IQ PRG discovery, sideload, and visible-delete support with tests
• adds Garmin Express-style tabs for activities, workouts, maps, and Connect IQ
• revamps the main PyQt window with a persistent device/status header and cleaner music actions
• updates Linux packaging dependencies for the Qt xcb runtime issue and documents an Ubuntu 22.04 packaging workflow template

Issue context

Reviewed open issue #2. This branch addresses the source/runtime side of the reported xcb dependency problem and adds a compatible build path/template for Ubuntu 22.04 to avoid newer-glibc release artifacts. It does not auto-close the issue because the active GitHub Actions workflow could not be committed with the current token scope and release artifacts still need to be produced from CI.

Validation

• python -m compileall -q src
• PYTHONPATH=src python -m pytest -q
• QT_QPA_PLATFORM=offscreen timeout 8s python -m garmin_penguin_express from a fresh editable install in /tmp/gpe-fresh-venv
• python -m build --wheel
• ./packaging/build_deb.sh
• bash -n packaging/build_deb.sh packaging/build_appimage.sh packaging/build_rpm.sh packaging/build_arch.sh

Notes

• Hardware validation with a physical Garmin watch was not available in this environment, so MTP-facing behavior is covered with fake mount-tree tests.
• The active .github/workflows/package-linux.yml file is not in this PR because GitHub rejected workflow creation without the workflow OAuth scope. The ready-to-copy workflow template lives at packaging/github-actions/package-linux.yml.

Refs #2