feat: add _cnd conditional operator support and n8n 2.0+ executeWorkflowTrigger fix

Added:
- Support for all 12 _cnd operators in displayOptions validation (eq, not, gte, lte, gt, lt, between, startsWith, endsWith, includes, regex, exists)
- Version-based visibility checking with @version in config
- 42 new unit tests for _cnd operators

Fixed:
- n8n 2.0+ breaking change: executeWorkflowTrigger now recognized as activatable trigger
- Removed outdated validation blocking Execute Workflow Trigger workflows

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

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

dist/utils/node-type-utils.js

@@ -95,11 +95,6 @@ function isTriggerNode(nodeType) {
     return specificTriggers.includes(normalized);
 }
 function isActivatableTrigger(nodeType) {
-    const normalized = normalizeNodeType(nodeType);
-    const lowerType = normalized.toLowerCase();
-    if (lowerType.includes('executeworkflow')) {
-        return false;
-    }
     return isTriggerNode(nodeType);
 }
 function getTriggerTypeDescription(nodeType) {