fix: Windows spawn, prefab path, preview API, asset deps, error messages; add execute-context resource, tool descriptions, scene/script/asset tools

Bug fixes (verified against Cocos Creator 3.8.8):
- diagnostics: shell:true for .cmd/.bat on Windows (T125/T126)
- prefabs: duplicatePrefab target resolves under assets/ (T420)
- cocos-project: add preview.open candidate for 3.8.8 (T444)
- assets-advanced: detect directory assets in inspectAssetDependencies (T110)
- scene: improve component-not-found errors with compilation hint (T429)

Documentation improvements:
- tool-registry: add enum and injected vars to execute_javascript, path format examples, asset ref limitation note
- resources: add cocos://mcp/execute-context resource with variables, patterns, pitfalls

New tools (core 37->38, full 101->110):
- scene-management: create_scene, query_scene_state (core), copy_paste_node, rename_node, reparent_node
- scripts: create_script with component/plain templates
- prefabs: create_prefab
- assets-advanced: batch_asset_ops, find_unused_assets

test/tool-registry.test.js

@@ -21,7 +21,7 @@ function createRegistry(profile, projectPath = path.resolve('/tmp/funplay-cocos-
 
 test('core profile exposes the documented focused tool set', () => {
   const tools = createRegistry('core').listTools();
-  assert.equal(tools.length, 37);
+  assert.equal(tools.length, 38);
   assert.equal(tools.some((tool) => tool.name === 'execute_javascript'), true);
   assert.equal(tools.some((tool) => tool.name === 'get_editor_state'), true);
   assert.equal(tools.some((tool) => tool.name === 'get_tool_catalog'), true);
@@ -31,12 +31,13 @@ test('core profile exposes the documented focused tool set', () => {
   assert.equal(tools.some((tool) => tool.name === 'get_performance_snapshot'), true);
   assert.equal(tools.some((tool) => tool.name === 'list_project_instructions'), true);
   assert.equal(tools.some((tool) => tool.name === 'set_selection'), true);
+  assert.equal(tools.some((tool) => tool.name === 'query_scene_state'), true);
   assert.equal(tools.some((tool) => tool.name === 'write_file'), false);
 });
 
 test('full profile exposes all built-in tools', () => {
   const tools = createRegistry('full').listTools();
-  assert.equal(tools.length, 101);
+  assert.equal(tools.length, 110);
   assert.equal(tools.some((tool) => tool.name === 'write_file'), true);
   assert.equal(tools.some((tool) => tool.name === 'edit_prefab_json'), true);
   assert.equal(tools.some((tool) => tool.name === 'create_project_skill'), true);