Modern Inspector Outstanding Issues

[vmoroz]

Modern Inspector Outstanding Issues

Follow-ups from PR #15328 (Add support for modern inspector)

• Implement the NetworkIOAgent pathway so the modern inspector can fetch network resources on Windows (ReactInspectorHostTargetDelegate::loadNetworkResource in vnext/Microsoft.ReactNative/ReactHost/ReactHost.cpp). Source: PR description and docs/modern-inspector-details.md.
• Enrich the host target metadata that we expose to the inspector (reuse the app identity and current debugger naming instead of the placeholder string). Tracked in review thread Add support for modern inspector #15328 (comment) and issue Improve the page name that shows up in the debugger's page/target list #15342.
• Replace the temporary inspector page name ("React Native Windows (Experimental)") with the final identity we want to surface in DevTools. Tracked in review thread Add support for modern inspector #15328 (comment) and issue Improve the page name that shows up in the debugger's page/target list #15342.
• Decide whether DevSupportManager::OpenDevTools should remain and, if so, wire it up to the active dev server configuration instead of the baked-in localhost:8081 default (vnext/Shared/DevSupportManager.cpp).
• Extract the variadic string_format helper out of DevServerHelper (or replace it) so we stop hand-rolling snprintf plumbing (vnext/Shared/DevServerHelper.h).
• Track modern inspector parity for Chakra-based runtimes (Chakra still falls back to legacy debugging). Source: docs/modern-inspector-details.md.
• Provide the real process ID to the RuntimeSamplingProfile constructor in HermesRuntimeTargetDelegate.cpp
• Remove support for the old sampling profiler and all the related Hermes wiring for it.

Follow-ups noted in prototype PR #13008 (Wire up Fusebox in react-native-windows)

• Defer inspector setup in ReactNativeHost until the first instance reload so feature flags can be toggled after host construction (comment: Wire up Fusebox in react-native-windows #13008 (comment)).
• Fix the debugger paused flyout dismissing itself when the app window is resized (comment: Wire up Fusebox in react-native-windows #13008 (comment)).
• Relocate the Ctrl+Shift+I dev tools shortcut wiring to a non-hacky location that can see both DevSettings and all active XamlRoots (comment: Wire up Fusebox in react-native-windows #13008 (comment)).
• Revisit the dedicated inspector serial queue to confirm we tear everything down safely; we may need additional lifetime management (comment: Wire up Fusebox in react-native-windows #13008 (comment)).