fix: webhook and 4 other nodes incorrectly marked as non-triggers

Fixed issue where Docker images using sql.js adapter returned boolean fields
as strings, causing is_trigger=0 to evaluate as true instead of false.

Changes:
- Added convertIntegerColumns() to sql.js adapter to convert SQLite integers
- Updated server.ts and node-repository.ts to use Number() conversion as backup
- Added test script to verify fix works with sql.js adapter

This fixes webhook, cron, interval, and emailReadImap nodes showing
isTrigger: false in Docker deployments.

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

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

src/mcp/server.ts

@@ -331,9 +331,9 @@ export class N8NDocumentationMCPServer {
         category: node.category,
         package: node.package_name,
         developmentStyle: node.development_style,
-        isAITool: !!node.is_ai_tool,
-        isTrigger: !!node.is_trigger,
-        isVersioned: !!node.is_versioned,
+        isAITool: Number(node.is_ai_tool) === 1,
+        isTrigger: Number(node.is_trigger) === 1,
+        isVersioned: Number(node.is_versioned) === 1,
       })),
       totalCount: nodes.length,
     };