docs: R-97 shipped; N.5 gains its four legs; ops results recorded

R-97 collapsed to its shipped one-liner in ROADMAP and closed in OPEN-ITEMS.

PROMPT-TEMPLATE N.5 now names FOUR coupled artifacts instead of two: the
capability map, ROADMAP, the owning architecture doc (ruled as S-1 in CONTEXT.md
but never reflected in the template CC actually reads, so it bound nobody), and
OPEN-ITEMS.md. Tasks must now report which register rows they opened, closed or
re-ranked.

Ops: R-90 swap done (interim; CX33 still blocked), R-95 mitigation armed but zero
snapshots taken so it moves to WATCHING rather than closed, R-91 gate still not
satisfied. CONTEXT.md datastore path corrected to /mnt/pbs-datastore.

CONTEXT.md

@@ -1019,7 +1019,9 @@ or retiring it is → **R-83**.
   over SSH** to a forced-command `felhom-peersync` script (pull rejected: weakens immediate
   revocation; HTTPS API rejected: new binary + third public port). Endpoint = the dev
   `felhom-hetzner` box, provisioned by the NEW runbook `documentation/runbooks/offsite-endpoint.md`
-  (WG on **443/udp**, subnet 10.77.0.0/24, PBS datastore `felhom-offsite` at `/srv/pbs-felhom`,
+  (WG on **443/udp**, subnet 10.77.0.0/24, PBS datastore `felhom-offsite` at `/mnt/pbs-datastore`
+  — a 100 GiB Hetzner Cloud Volume attached 2026-07-27 06:29:40 UTC; the pre-migration copy at
+  `/srv/pbs-felhom` is 13 G of dead weight on `/` awaiting R-91's go-ahead —
   nftables drop-all + wg0-only 8007, `ep0.felhom.eu` grey-cloud). Hub: `wg_endpoints`/`wg_peers` +
   /32 allocator + `/admin/wg/*` (global-key, pubkey-in-body) + `internal/wgsync` (FixedHostKey pin
   + **pinned-type HostKeyAlgorithms — live-caught bug**: multi-hostkey sshd presented ECDSA vs the