fix: refactor telemetry system with critical improvements (v2.14.1)

Major improvements to telemetry system addressing code review findings:

Architecture & Modularization:
- Split 636-line TelemetryManager into 7 focused modules
- Separated concerns: event tracking, batch processing, validation, rate limiting
- Lazy initialization pattern to avoid early singleton creation
- Clean separation of responsibilities

Security & Privacy:
- Added comprehensive input validation with Zod schemas
- Sanitization of sensitive data (URLs, API keys, emails)
- Expanded sensitive key detection patterns (25+ patterns)
- Row Level Security on Supabase backend
- Added data deletion contact info (romuald@n8n-mcp.com)

Performance & Reliability:
- Sliding window rate limiter (100 events/minute)
- Circuit breaker pattern for network failures
- Dead letter queue for failed events
- Exponential backoff with jitter for retries
- Performance monitoring with overhead tracking (<5%)
- Memory-safe array limits in rate limiter

Testing:
- Comprehensive test coverage (87%+ for core modules)
- Unit tests for all new modules
- Integration tests for MCP telemetry
- Fixed test isolation issues

Data Management:
- Clear user consent in welcome message
- Batch processing with deduplication
- Automatic workflow flushing

BREAKING CHANGE: TelemetryManager constructor is now private, use getInstance()

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

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

package.json

@@ -1,6 +1,6 @@
 {
   "name": "n8n-mcp",
-  "version": "2.14.0",
+  "version": "2.14.1",
   "description": "Integration between n8n workflow automation and Model Context Protocol (MCP)",
   "main": "dist/index.js",
   "bin": {