test(p0-r3): add comprehensive test suite for template configuration feature

Add 85+ tests covering all aspects of P0-R3 implementation:

**Integration Tests**
- Template node configs database operations (CREATE, READ, ranking, cleanup)
- End-to-end MCP tool testing with real workflows
- Cross-node validation with multiple node types

**Unit Tests**
- search_nodes with includeExamples parameter
- get_node_essentials with includeExamples parameter
- Template extraction from compressed workflows
- Node configuration ranking algorithm
- Expression detection accuracy

**Test Coverage**
- Database: template_node_configs table, ranked view, indexes
- Tools: backward compatibility, example quality, metadata accuracy
- Scripts: extraction logic, ranking, CLI flags
- Edge cases: missing tables, empty configs, malformed data

**Files Modified**
- tests/integration/database/template-node-configs.test.ts (529 lines)
- tests/integration/mcp/template-examples-e2e.test.ts (427 lines)
- tests/unit/mcp/search-nodes-examples.test.ts (271 lines)
- tests/unit/mcp/get-node-essentials-examples.test.ts (357 lines)
- tests/unit/scripts/fetch-templates-extraction.test.ts (456 lines)
- tests/fixtures/template-configs.ts (484 lines)
- P0-R3-TEST-PLAN.md (comprehensive test documentation)

**Test Results**
- Manual testing: 11/13 nodes validated with examples
- Code review: All JSON.parse calls properly wrapped in try-catch
- Performance: <1ms query time verified

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

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

package.runtime.json

@@ -1,6 +1,6 @@
 {
   "name": "n8n-mcp-runtime",
-  "version": "2.14.7",
+  "version": "2.15.0",
   "description": "n8n MCP Server Runtime Dependencies Only",
   "private": true,
   "dependencies": {