Basecamp Enhancements and Maintenance: Testnet v0.5

Track: Basecamp Enhancements and Maintenance Track

Estimated date of completion: Testnet v0.5 launch

Remove the deprecated paths, plus notifications and the status bar.

Risks

Risk	(Accept, Own, Mitigation)
December holidays

Fix all bugs raised against Basecamp this cycle
Remove deprecated app types, so only one UI app type remains
- QML-only apps
- Legacy ui (C++ widget) apps
- Today’s ui_qml apps with a built-in C++ backend, replaced by a QML view + core-module backend
App and system notifications
Bottom status bar: running nodes, indicators, rescue indicator
Settings page leftovers
Open links in the external browser
Stretch: translations groundwork; workspaces / docking design