feat: BambuGUI — native PySide6 desktop app to replace Docker web stack

[synman]

Summary

Replace web browser + Docker stack with native PySide6 desktop application for Bambu printer management.

Pending Panels

1. Discovery panel
2. Dashboard panel
3. Camera panel
4. Controls panel
5. Files panel
6. Filament panel
7. Charts panel
8. Settings panel

Architecture

Full plan documented in copilot-cli session fcc4cd61. Core infrastructure done, all 8 panels pending.

Migrated from copilot-cli session fcc4cd61