feat: propagate invocation-site names for dynamic components in debugRenderTree

For dynamic component invocations like `<this.Foo>` and `<@Greeting>`,
the debug render tree now shows the invocation-site name instead of
'(unknown template-only component)'.

This works by extracting the Reference's debugLabel in
VM_RESOLVE_DYNAMIC_COMPONENT_OP and VM_RESOLVE_CURRIED_COMPONENT_OP,
and setting it as the ComponentDefinition's debugName when no name
is already present.

- `<this.Foo>` → name: "Foo"
- `<@Greeting>` → name: "Greeting"

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: NullVoxPopuli

packages/@glimmer-workspace/integration-tests/test/debug-render-tree-test.ts

@@ -185,9 +185,10 @@ class DebugRenderTreeTest extends RenderTest {
 
     this.assert.ok(componentNode, 'found a component child node');
 
+    // For <@Greeting>, the invocation-site name "Greeting" is used
     this.assert.strictEqual(
       componentNode?.name,
-      'HelloWorld',
+      'Greeting',
       `dynamic <@X> component name (got "${componentNode?.name}")`
     );
   }

packages/@glimmer/runtime/lib/compiled/opcodes/component.ts

@@ -154,8 +154,9 @@ APPEND_OPCODES.add(VM_PUSH_COMPONENT_DEFINITION_OP, (vm, { op1: handle }) => {
 
 APPEND_OPCODES.add(VM_RESOLVE_DYNAMIC_COMPONENT_OP, (vm, { op1: _isStrict }) => {
   let stack = vm.stack;
+  let ref = check(stack.pop(), CheckReference);
   let component = check(
-    valueForRef(check(stack.pop(), CheckReference)),
+    valueForRef(ref),
     CheckOr(CheckString, CheckCurriedComponentDefinition)
   );
   let constants = vm.constants;
@@ -182,6 +183,14 @@ APPEND_OPCODES.add(VM_RESOLVE_DYNAMIC_COMPONENT_OP, (vm, { op1: _isStrict }) =>
     definition = constants.component(component, owner);
   }
 
+  if (DEBUG && !isCurriedValue(definition) && !definition.resolvedName && !definition.debugName) {
+    let debugLabel = ref.debugLabel;
+    if (debugLabel) {
+      // Extract the last segment of the path (e.g. "this.Foo" → "Foo", "Foo" → "Foo")
+      definition.debugName = debugLabel.split('.').pop();
+    }
+  }
+
   stack.push(definition);
 });
 
@@ -217,6 +226,18 @@ APPEND_OPCODES.add(VM_RESOLVE_CURRIED_COMPONENT_OP, (vm) => {
     }
   }
 
+  if (DEBUG && definition && !isCurriedValue(definition) && !definition.resolvedName && !definition.debugName) {
+    let debugLabel = ref.debugLabel;
+    if (debugLabel) {
+      // Extract the component name from the arg path (e.g. "@Greeting" → "Greeting")
+      let name = debugLabel.split('.').pop()!;
+      if (name.startsWith('@')) {
+        name = name.slice(1);
+      }
+      definition.debugName = name;
+    }
+  }
+
   stack.push(definition);
 });