v0.263.2: the undo keeps the probe of the pinned version (R-637)

Found live on 9202 (romm): .felhom.yml flows into the stack dir on every
catalog sync, so "the old .felhom.yml" saved at update time was already the
new one, and the serving old version was judged with the new probe.

New record applied-meta/.felhom.yml, written whenever a version is pinned
(deploy, adoption, pin advance) and put back by the undo, like
applied-compose.yml. The fixture now places the new file at sync time.

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

CHANGELOG.md

@@ -1,3 +1,23 @@
+## v0.263.2 — the undo keeps the probe of the PINNED version, recorded when it was pinned (2026-09-23, R-637)
+
+**MinAgent: 0.131.0** (unchanged). No new strings.
+
+**The second thing the live proof on 9202 caught.** v0.263.1 still judged romm's serving old version
+"did not start" — this time `last: health check failing` on port 8999. The undo's "old `.felhom.yml`"
+was saved AT UPDATE TIME, from the stack dir — but `.felhom.yml` flows into the stack dir on every
+catalog SYNC (`09` §5.4: it is never frozen), so by the time anyone presses Update the stack dir already
+holds the NEW version's file. v0.263.0's unit tests wrote the new file at PULL time — the wrong moment
+— and passed.
+
+**Fix:** a new record, `<stack>/applied-meta/.felhom.yml` — the `.felhom.yml` of the PINNED version,
+written when a version is pinned (deploy, pin adoption, the guarded update's pin advance) and put back
+by the undo's pin-back, exactly as `applied-compose.yml` is for the definition. The update keeps THAT
+file for the undo. **An app pinned before v0.263.2 has no record yet**: its undo probes with the
+current file, and the job says so in the log; the record appears at its next pin (deploy or update).
+The test fixture now puts the new `.felhom.yml` in place at SYNC time, before the press; red-proofs:
+v0.263.1's read of the stack dir fails `TestUndo_UsesTheOldProbe`; a pin advance that records nothing
+fails `TestUndo_PinningRecordsThatVersionsProbe`.
+
 ## v0.263.1 — the undo asks the OLD probe even when the new one has marked the app unhealthy (2026-09-23, R-637)
 
 **MinAgent: 0.131.0** (unchanged). No new strings.