Repair File Sync, Conflict & Replica Consistency Bugs

The likely issue is a contract mismatch around file synchronization, local/remote replicas, version identity, conflict detection, concurrent edits, rename/delete races, offline changes, partial upload/download, duplicate events, retry, and conflict recovery. I would first define the invariant: Sync must preserve user data and causal intent: no replica may silently overwrite a concurrent change, resurrect a confirmed deletion, or treat an ambiguous partial transfer as a completed version. Then I would trace the smallest owning boundary, keep VERIFIED facts separate from LIKELY/UNKNOWN state, apply or propose the narrowest repair, and add deterministic normal, boundary, failure, retry/cancellation, and recovery tests. The workflow preserves authorization, privacy, security policy, public interfaces, user-visible behavior, and documented ownership. With repository/workspace access, findings can map to exact paths and focused local validation; with partial evidence, the result remains an explicit diagnosis/evidence map with no invented execution claims.