docs: fix connection keys documentation to say "node names" not "node IDs" (#510) (#511)

The documentation incorrectly stated connection keys should be "node IDs"
when n8n actually requires "node names". This caused workflow creation
failures for AI-generated workflows.

Changes:
- tools-n8n-manager.ts: "Keys are source node names (the name field, not id)"
- n8n-create-workflow.ts: "Keys are source node names (not IDs)"
- Fixed example: "Webhook"/"Slack" instead of "webhook_1"/"slack_1"
- get-template.ts: clarified "source node names"

Closes #510

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

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

Co-authored-by: Romuald Członkowski <romualdczlonkowski@MacBook-Pro-Romuald.local>
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

src/mcp/tools-n8n-manager.ts

@@ -46,9 +46,9 @@ export const n8nManagementTools: ToolDefinition[] = [
             }
           }
         },
-        connections: { 
-          type: 'object', 
-          description: 'Workflow connections object. Keys are source node IDs, values define output connections' 
+        connections: {
+          type: 'object',
+          description: 'Workflow connections object. Keys are source node names (the name field, not id), values define output connections'
         },
         settings: {
           type: 'object',