Bug: index.ui has VBox with 3 urlwidget subwidgets (top.ui, center.ui, bottom.ui).
When RenderUrlWidget dispatched through ActionDispatcher, loadWidget called
onWidgetLoaded which replaced the ENTIRE root widget. The last urlwidget to
finish loading (bottom.ui) overwrote top.ui and center.ui.
Fix: RenderUrlWidget now maintains local state (loadedWidget) and renders
loaded content in-place. Added ActionDispatcher.loadWidgetInPlace() that loads
via callbacks without calling onWidgetLoaded. Each urlwidget replaces only
itself, preserving sibling widgets in the parent container.
- DevLogStore: centralized log store with Flow-based observation (INFO/WARN/ERROR/EXCEPTION levels)
- DevHttpInterceptor: capture request/response pairs with timing and body details
- DevPanel: bottom panel with Logs/Network/Errors tabs, expandable entries, JSON formatting
- Integrated into BricksHttp (all HTTP methods), BricksParser, ActionDispatcher, Main
- Move Main.kt from shared/ to test/generic-client/ (library module should not have main)
- Add test/generic-client/ as generic bricks-mp desktop host with DevMode toggle
- Add kotlinx-datetime dependency for timestamp handling
- Add materialIconsExtended for DevPanel icons
