docs: close out the instruction arc — t740 corrected on evidence, registers, ledger, S-37

target-selection.md said demo-hp has no off-site tier. Measured first: pvesm list felhom-pbs on the
box returns two snapshots in demo-hp's OWN namespace (2026-07-28, 2026-08-04) against ep0's
felhom-offsite. The claim was TRUE WHEN WRITTEN and went stale when F10 resolved 2026-07-23. The
measurement is kept in an HTML comment beside the corrected sentence. This file decides which
machine may be destroyed, so the sentence was load-bearing, not cosmetic.

R-229(b) CLOSED (agent 175 -> 99 eff). R-230(b) CLOSED (symlink, proven from fresh sessions).
R-230(a) part-actioned -- three false statements fixed, WARN loop added, bulk ruling still owed.

S-37: a claim in an instruction file is checked, not trusted.

CONTEXT.md

@@ -17,6 +17,33 @@
 
 ## Standing rulings
 
+**S-37 — A CLAIM IN AN INSTRUCTION FILE IS CHECKED, NOT TRUSTED (2026-08-06, R-229/R-230 close-out).**
+
+1. **The workspace-root `CLAUDE.md` is a SYMLINK** to `documentation/runbooks/workspace-CLAUDE.md`.
+   One file reachable by two paths cannot diverge; two files kept identical by hand must be policed
+   forever. Check 5 accepts either shape — a clone elsewhere may still have two files — and for the
+   link it asserts the target **resolves**, because a dangling link means the workspace instructions
+   load nothing at all and there is no content left to notice is wrong.
+2. **A citation that calls a register item OPEN is now gated** (check 7). The trigger is an
+   **openness claim**, not any citation: policing every mention would fire on ~30 legitimate
+   provenance citations and the gate would be switched off, which is R-29's own lesson.
+3. **`MEMORY.md` is WARNed, never FAILed, on content.** Claude writes it between sessions; a hard
+   failure would refuse a human's push over a line no human typed. The warning is aimed at the model
+   that will next edit the file, which is what makes the loop self-correcting.
+4. **A scan is not evidence until its false-positive class is known.** Three "expired statements"
+   reported on 2026-08-06 were all filenames matched inside markdown link targets, while the one real
+   expired claim carried no ISO date and was missed. Link targets are stripped before any content
+   judgement now.
+5. **A red-proof that does not go red is a finding about the instrument.** Two shipping bugs in check
+   7 were found exactly that way — a state marker that is not self-closing (which made the check read
+   its own founding case as open), and a CLOSED exemption applied line-wide instead of to the
+   citation's clause.
+6. **Correct a runbook only after measuring.** `target-selection.md` said demo-hp had no off-site
+   tier; `pvesm list felhom-pbs` on the box returns two snapshots in its own namespace, newest
+   2026-08-04. The claim was true when written and went stale when F10 resolved. This file decides
+   which machine may be destroyed, so a wrong statement about what a machine holds is how a drill
+   lands somewhere it should not.
+
 **S-36 — THE AUTO-MEMORY STORE IS BACKED UP, NOT COMMITTED; AND THE WORKSPACE IS INSTALLABLE
 (2026-08-06, R-229 part 2).**