A

Slice 109 - Sync Execution Boundaries

Scope#

Move sync run execution effects out of SyncWorkflow.service while preserving foreground and background sync behavior.

Why Now#

After slice 108, workflows/sync/service.py is the largest production file. Its evaluate(...) method is already policy-oriented and delegates most cursor logic to sync policy modules. Its run(...) method still mixes high-level sync orchestration with foreground Ingest execution, background queueing, pending claim writes, worker spawn failure handling, failed ledger writes, absorbed ledger writes, and started summary rows.

Cosmic Python chapter 04 separates orchestration logic from interfacing code, and chapter 13 keeps dependencies explicit. Applied here: SyncWorkflow should own the public status/run/evaluate use case surface, while a focused executor owns the side effects that turn evaluated work items into run records and ledger updates.

In Scope#

  • Add workflows/sync/execution.py with SyncRunExecutor.
  • Keep SyncWorkflow.run(...) as the public workflow verb.
  • Move foreground ingest execution, background queueing, worker spawn failure handling, pending/failed/absorbed ledger writes, and started rows into the executor.
  • Add an architecture guard so service.py does not regrow execution mechanics.

Out of Scope#

  • Sync policy changes.
  • Public CLI command changes.
  • Background default-mode changes.
  • Ledger schema changes.

Verification#

  • Focused sync workflow tests for foreground/background/failure paths.
  • Architecture guard for sync service/execution split.
  • Public sync status --json dogfood.
  • Full pytest, Ruff, and diff hygiene.