refactor: Phase 6 - Complete migration, remove legacy files
BREAKING CHANGE: Legacy worker files removed, Worker struct simplified
Changes:
1. worker.go - Simplified to 8 fields using composed dependencies:
- runLoop, runner, metrics, health (from new packages)
- Removed: server, queue, running, datasetCache, ctx, cancel, etc.
2. factory.go - Updated NewWorker to use new structure
- Uses lifecycle.NewRunLoop
- Integrates jupyter.Manager properly
3. Removed legacy files:
- execution.go (1,016 lines)
- data_integrity.go (929 lines)
- runloop.go (555 lines)
- jupyter_task.go (144 lines)
- simplified.go (demonstration no longer needed)
4. Fixed references to use new packages:
- hash_selector.go -> integrity.DirOverallSHA256Hex
- snapshot_store.go -> integrity.NormalizeSHA256ChecksumHex
- metrics.go - Removed resource-dependent metrics temporarily
5. Added RecordQueueLatency to metrics.Metrics for lifecycle.MetricsRecorder
Worker struct: 27 fields -> 8 fields (70% reduction)
Build status: Compiles successfully