feat(debugger): debug Flutter apps through the Flutter debug adapter (#1474)

Dart projects that depend on the Flutter SDK were debugged through
`dart debug_adapter`, which cannot start a program importing dart:ui and has no
hot reload. A session now uses `flutter debug_adapter` when the program's or the
working directory's pubspec.yaml depends on the Flutter SDK, or when an attach
configuration asks for it (add-to-app: vm-service-uri and device map to the
adapter's attach arguments). Hot Reload and Hot Restart are sent over DAP and
appear in the toolbar of Dart sessions. Dart files also get a debug configuration.

Co-authored-by: payailk <[email protected]>

src/features/debugger/ui/DebugToolWindow.tsx

@@ -32,6 +32,7 @@ import {
   selectSession,
   selectThread,
   revealFrame,
+  rootOf,
   sessionSupports,
   useDebug,
   type DebugSession,
@@ -200,6 +201,13 @@ export function DebugToolWindow() {
         <ToolButton action="debug.stepInto" icon="step-into" />
         <ToolButton action="debug.stepOut" icon="step-out" />
         <span className={styles.sep} aria-hidden />
+        {rootOf(active).adapter === "dart" && (
+          <>
+            <ToolButton action="debug.hotReload" icon="hot-reload" />
+            <ToolButton action="debug.hotRestart" icon="refresh" />
+            <span className={styles.sep} aria-hidden />
+          </>
+        )}
         <IconButton
           icon="view-breakpoints"
           action="debug.viewBreakpoints"