v1.22.0: Filter unlabeled container events & debounce optimization

Features & Performance Improvements

• Unlabeled Container Filtering: Docker container lifecycle events are now checked for Cloudflare tunnel labels (cf.tunnel.*, cloudflared.*, cftunnel.*, tunnel.*, shorthand aliases). Events from unrelated containers (such as databases, cron jobs, or monitoring agents) are ignored, avoiding unnecessary debounced sync loops and Cloudflare API queries.
• Connector & Active Service Preservation: Lifecycle events for the cloudflared connector container and previously active services in memory are always processed, ensuring container restarts and deletions cleanly trigger ingress and DNS reconciliation.
• Removed Premature kill Action: Removed kill from CONTAINER_LIFECYCLE_ACTIONS to avoid premature debounce triggers before container processes have finished their shutdown grace period; process termination (die) and status updates (stop) are used instead.
• Configurable Override: Introduced FILTER_UNLABELED_EVENTS setting (default: true). Set to false if all container events must trigger synchronization.

Validation

• Comprehensive unit tests covering label detection, event suppression, connector handling, and tombstone tracking.
• All 12 CI gates passed (CodeQL, continuous fuzzing, unit & container smoke gates, OSV-Scanner).
• Independent code review and squash merge completed by MustermenschAlex in #190.