fix: update test assertions for ON CONFLICT saveNode SQL

Tests expected old INSERT OR REPLACE SQL, updated to match new
INSERT INTO ... ON CONFLICT(node_type) DO UPDATE SET pattern.

Conceived by Romuald Członkowski - https://www.aiadvisors.pl/en

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

tests/unit/database/node-repository-community.test.ts

@@ -120,7 +120,7 @@ class MockPreparedStatement implements PreparedStatement {
     }
 
     // saveNode - INSERT OR REPLACE
-    if (this.sql.includes('INSERT OR REPLACE INTO nodes')) {
+    if (this.sql.includes('INSERT INTO nodes')) {
       this.run = vi.fn((...params: any[]): RunResult => {
         const nodes = this.mockData.get('community_nodes') || [];
         const nodeType = params[0];

tests/unit/database/node-repository-core.test.ts

@@ -91,7 +91,7 @@ describe('NodeRepository - Core Functionality', () => {
       repository.saveNode(parsedNode);
 
       // Verify prepare was called with correct SQL
-      expect(mockAdapter.prepare).toHaveBeenCalledWith(expect.stringContaining('INSERT OR REPLACE INTO nodes'));
+      expect(mockAdapter.prepare).toHaveBeenCalledWith(expect.stringContaining('INSERT INTO nodes'));
 
       // Get the prepared statement and verify run was called
       const stmt = mockAdapter._getStatement(mockAdapter.prepare.mock.lastCall?.[0] || '');

tests/unit/database/node-repository-outputs.test.ts

@@ -56,7 +56,7 @@ describe('NodeRepository - Outputs Handling', () => {
       repository.saveNode(node);
 
       expect(mockDb.prepare).toHaveBeenCalledWith(`
-      INSERT OR REPLACE INTO nodes (
+      INSERT INTO nodes (
         node_type, package_name, display_name, description,
         category, development_style, is_ai_tool, is_trigger,
         is_webhook, is_versioned, is_tool_variant, tool_variant_of,