JSX ref forwarding + general-purpose Dart Node VS Code extension

[MelbourneDeveloper]

TLDR

Finish the JSX DSL by adding ref forwarding (with a cloneElement fix so ref/key survive >> recomposition) and rebrand the VS Code extension into a general-purpose "Dart Node" extension with four basic commands.

What Was Added?

• JSX ref forwarding (packages/dart_node_react): optional ref: (a JsRef from createRef) on $div, $input, $button, $textarea, $a, $select, $form, $img, $video, $audio.
• cloneElementWithRawChildren helper in react.dart (delegates to the existing clone machinery; no duplication).
• vscode.version binding in dart_node_vsix.
• Four general-purpose "Dart Node" extension commands: dartNode.hello (greeting), dartNode.showVersion (vscode.version), dartNode.echo (input box → message), dartNode.count (persisted run counter via globalState memento).
• Tests: JSX ref leaf + recomposition tests; a globalState memento round-trip self-check + assertion.

What Was Changed or Deleted?

• El recomposition now uses cloneElement instead of createElement. React 18 hoists ref/key out of props, so rebuilding from props dropped them whenever >> attached children; cloneElement preserves ref/key/props. This also fixes a latent key-drop on recomposition.
• Fixed the Memento binding (extension_context.dart): get/update/keys now dispatch on the memento object via callMethod instead of unnamed @JS() externals that resolved to nonexistent globals (globalThis._mementoGet). The previous binding threw at runtime for any caller.
• Rebranded the extension: dart-node-vsix-test / "Dart Node VSIX Test" → dart-node / "Dart Node"; ids dartNodeVsix.* → dartNode.*; output channel / status bar / log labels → "Dart Node"; extensionId and package-lock.json name updated to match.
• Deleted test/jsx/jsx_dsl_test.dart — a strict subset of jsx_test.dart (removes duplication).

How Do The Automated Tests Prove It Works?

• packages/dart_node_react/test/jsx_test.dart (18 tests, Chrome): ref forwards to the rendered DOM node and ref survives recomposition when children are added with >> assert ref.jsRef.current is non-null after render — the second exercises the $button(ref:) >> 'Save' path that fails without the cloneElement fix. All existing DSL tests (text/nested/events/fragment/conditional/numeric/keys/spread/override) still pass.
• packages/dart_node_vsix/test/suite/extension_activation_test.dart: globalState memento round-trips through the binding asserts the activation self-check wrote 7 and read it back. Because that round-trip runs inside activate, a broken memento binding fails activation and the entire suite — so the suite guards it.
• packages/dart_node_vsix/test/suite/commands_test.dart: asserts all five dartNode.* commands are registered.
• Additionally verified locally (make ci green across all three tiers): dart analyze and dart format clean; cspell clean; extension.dart compiles dart compile js -O2 with the memento dispatching globalState.get(...) / globalState.update(...) on the object (no global lookups).

Spec / Doc Changes

• docs/plans/JSX_IMPLEMENTATION_PLAN.md: replaced "Open Questions"/"Next Steps" with Resolved Decisions, Phase Status, and a TODO checklist (Phase 1 shipped; later phases deferred).
• packages/dart_node_vsix/README.md: added a "Bundled extension: Dart Node" section documenting the commands.

Breaking Changes

• None for published package APIs. The library changes are additive (new optional ref params, new vscode.version getter) or bug fixes (the Memento binding now works). The id/manifest rename (dartNodeVsix.* → dartNode.*, Nimblesite.dart-node-vsix-test → Nimblesite.dart-node) affects only the bundled demo extension (publish_to: none), not a published surface.