feat(webui): settings & configuration panel (Issue #160)
- useSettings.js: PID parameter catalogue, step-response simulation,
ROS2 parameter apply via rcl_interfaces/srv/SetParameters, sensor
param management, firmware info extraction from /diagnostics,
diagnostics bundle export, JSON backup/restore, localStorage persist
- SettingsPanel.jsx: 6-view panel (PID, Sensors, Network, Firmware,
Diagnostics, Backup); StepResponseCanvas with stable/oscillating/
unstable colour-coding; GainSlider with range+number input; weight-
class tabs (empty/light/heavy); parameter validation badges
- App.jsx: CONFIG tab group (purple), settings tab render, FLEET_TABS
set to gate ConnectionBar and footer for fleet/missions/settings
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>