c81df55dcb
Sibling shares source for the local cross-drive tier. Reuses the tier2Mirror seam, selectTier2TargetFrom (narrow source-drive seam extracted from selectTier2Target), tier2ReconcileRoots (pure extraction), tier2SafeRemove, the marker-LAST discipline and the recordTier2* helpers. Per-app paths are untouched. - shares_payload.go: deterministic _shares-manifest.json + best-effort passdb capture - tier2_shares.go: per-source-drive legs -> cross-drive target, payload, marker LAST - infra.SambaContainerName/SambaPassdbVolume/Mount: single source of truth for the container identity (renderer, stacks execs, backup execs, monitor all read it) - RESERVED-NAME finding: ValidateSMBShareName did NOT exclude a leading underscore, so "_shares" was an accepted share name. Now refused; RunAllTier2 additionally skips a "_shares" stack loudly as defense in depth. - fix: shareSourceDrive returned a slash-normalised path, which made the target selector's source-drive equality check miss (a group could target its own drive)