docs: backup verified IN the repository — snapshot b587f775, 118/118 + 40/40 (R-229)

58,158 files / 405.865 GiB in 27:56; 994 MiB added, 77 MiB stored -- the one-time full re-read
cost I/O, not storage, as predicted.

Also records a false alarm I raised against my own instrument: `restic ls <snapshot> <path>`
reported 0 of 40 archived memories because restic 0.18.0's path filter does not recurse into
subdirectories. The unfiltered listing shows all 40. An instrument that can drop results silently
is not a measurement -- and this one was measuring a safety property.

REPORT-instruction-trim-part2-2026-08-06.md

@@ -118,11 +118,23 @@ Including Claude auto-memory store: /mnt/5_hdd/felhom.eu/git/.claude-memory
 start backup on [/mnt/4_hdd/data /mnt/5_hdd/felhom.eu/git/.claude-memory]
 ```
 
+**Completed and verified in the repository.** Snapshot `b587f775`, 58,158 files / 405.865 GiB in
+27:56, `994.132 MiB added (77.440 MiB stored)` — 77 MiB stored for a 405 GiB re-read confirms the
+one-time cost was I/O, not storage. Contents: **161** `.claude-memory` entries — **118/118** top-level
+`.md` and **40/40** under `archive/`. The 03:07 snapshot holds `/mnt/4_hdd/data` only, so the two
+snapshots are a clean before/after in one listing.
+
+**A false alarm I raised against my own instrument.** The first check used
+`restic ls <snapshot> <path>` and reported **0 of 40** archive files — which read exactly like 40
+memories silently unprotected. It was wrong: restic 0.18.0's path filter lists entries *at* that path
+and does not recurse. The unfiltered listing shows all 40. Recorded because it is this project's own
+rule — *an instrument that can drop results silently is not a measurement* — biting a measurement made
+**to verify a safety property**.
+
 **Three caveats that make this weaker than "backed up" sounds:** the destination is on the **same
 physical disk** as the store; the DooPlex backup set has **no off-site leg**
 (`sync-hetzner-backups.sh` is jarrs.eu and pulls the other way); and `/opt/backup/scripts/` is itself
-**unversioned host state** (R-231). One-time cost: adding a path invalidated restic's parent match,
-so the first run re-reads 405 GiB — dedup keeps storage flat and later runs are incremental again.
+**unversioned host state** (R-231).
 
 ## 11. Rules report — first run