TODO-1.6: log lint blind spot — retired dirs masked by leaf-README route

Vault sanity check found archive/ and _agent/outputs/ (retired/unrouted
pre-0.6 trees) surviving in the live vault with only seed READMEs; the
permissive leaf-readme route matches before the retired-path check, so
/echo-health never flags them.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

TODO-1.6.md

@@ -46,4 +46,12 @@ they were unwrapped per instruction but repointing them would restore real graph
 
 *(add items here as the new plugin gets real use)*
 
-- [ ] —
+- [ ] **Lint blind spot: retired dirs masked by the leaf-README route** (found 2026-07-03).
+      `archive/` and `_agent/outputs/` are retired/unrouted pre-0.6 leftovers that survived
+      in the live vault holding only their seed READMEs — and the permissive `leaf-readme`
+      route (`^(.+/)?README\.md$`) matches first, so `vault_lint` never flagged them.
+      Fix: in the path-membership check, test the *directory* against retired/unknown
+      patterns even when the only file in it is a README (e.g. evaluate `dirname(path) + "/"`
+      against retired patterns before letting `leaf-readme` absolve the file), or drop the
+      seed-README exemption inside retired trees. Add a lint test seeding
+      `archive/notes/README.md` → must flag `retired-path`.