REPORT + CONTEXT: v0.275.0 released, floor 0.275.0

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0159rPz1ZhFKsS53msqPYxtS

CONTEXT.md

@@ -7,7 +7,17 @@
 >
 > Ask Claude Code: "Please update CONTEXT.md with what we did today"
 
-Last updated: 2026-09-25 night (v0.271.0 — automatic app updates, `09` §6.4 part 7; R-680, R-678; floor 0.271.0)
+Last updated: 2026-09-27 (v0.275.0 — a backup's data and its version travel together; floor 0.275.0)
+
+> **2026-09-27 — v0.275.0, floor 0.275.0 (MinAgent 0.131.0).** `backup/data_versions.go`: `stampDataFile` (called by the
+> DB leg, the volume leg and `RunAppBackupNow` — a new writer of a unit data file MUST call it), `foldUnitData`,
+> `RecoveryManifest.Data`; `captureRecoveryUnit(stack, dataRun)` keeps `compose/` when the pins moved since the data
+> (frozen); `unitVersionCheck`/`ErrUnitVersionMismatch` in the unit restore and the off-site reconstitute (which now
+> writes the snapshot's definition when versions differ); `unitDataTime` = THE unit data time (+ proven flag, R-699);
+> Tier 2 `DataDate`/`DataUnproven`; Tier 3 `offsiteDataTime`; `stacks.DumpStampSource` (optional guards interface) +
+> `ConversionCopy.Service`; `stacks.RestoredVersionPosition` + the restore pages' first sentence; R-695 single-flight
+> FB sync; R-691 `keptReadGroups`/`group_add` (CC-unattended decision, `07` §6.5); R-694 `restored_logins`.
+> D4 (open) option A is the built behaviour — `07` §6.6.
 
 > **2026-09-25 midday — v0.272.0, floor 0.272.0.** `web.noSpaceLine` (agent prefix `skipped: not enough space: `,
 > key `backup.tier.no_space`); `backup.SetUndoCopyRemover` → `stacks.RemoveUndoCopies` from `clearUpdateHoldAfterRestore`