test: add comprehensive unit tests for database, parsers, loaders, and MCP tools

- Database layer tests (32 tests):
  - node-repository.ts: 100% coverage
  - template-repository.ts: 80.31% coverage
  - database-adapter.ts: interface compliance tests

- Parser tests (99 tests):
  - node-parser.ts: 93.10% coverage
  - property-extractor.ts: 95.18% coverage
  - simple-parser.ts: 91.26% coverage
  - Fixed parser bugs for version extraction

- Loader tests (22 tests):
  - node-loader.ts: comprehensive mocking tests

- MCP tools tests (85 tests):
  - tools.ts: 100% coverage
  - tools-documentation.ts: 100% coverage
  - docs-mapper.ts: 100% coverage

Total: 943 tests passing across 32 test files
Significant progress from 2.45% to ~30% overall coverage

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/parsers/simple-parser.ts

@@ -187,9 +187,28 @@ export class SimpleParser {
   }
 
   private extractVersion(nodeClass: any): string {
+    // Try to get version from instance first
+    try {
+      const instance = typeof nodeClass === 'function' ? new nodeClass() : nodeClass;
+      
+      // Check instance baseDescription
+      if (instance?.baseDescription?.defaultVersion) {
+        return instance.baseDescription.defaultVersion.toString();
+      }
+      
+      // Check instance description version
+      if (instance?.description?.version) {
+        return instance.description.version.toString();
+      }
+    } catch (e) {
+      // Ignore instantiation errors
+    }
+    
+    // Check class-level properties
     if (nodeClass.baseDescription?.defaultVersion) {
       return nodeClass.baseDescription.defaultVersion.toString();
     }
+    
     return nodeClass.description?.version || '1';
   }