docs: open patterns run when the harness can bind them; README's tenth op; C29 backstop

Fieldtest truth pass (composites-use, B1/S1/S2/S3):

- The "running an open pattern standalone refuses" sentence was wrong — and
  it was this cycle's own ratification prose, not code. Reality (ratified
  as-is): the harness binds input roles to archive columns BY NAME (C26), so
  an open pattern whose roles match the data runs standalone as a matter of
  design; what refuses, by name, is a role the harness cannot bind, or the
  run surface's other gates (bias/tap, free knobs). The authoring guide's
  input row now states exactly that; C24's input row ("only compile/
  bootstrap require it bound") and the glossary's "requires them bound"
  were already accurate and stand.
- README enumerated nine op kinds — the tenth (use) added (S2).
- The use-seam C29 doc gate is stated as what it is: a backstop — the
  register verb already gates both input forms, so it fires only for store
  content written before C29 or through the raw in-crate path (S3,
  ratified).

B1's fieldtest classification was bug->debug; overridden to ratify+document:
the observed behaviour is C26-coherent and useful (quick-testing a pattern
against real data), the defect was the sentence. Minuted on #317.

refs #317, refs #339

docs/design/contracts/c24-blueprint-data.md

@@ -171,7 +171,9 @@ permission §"Enforcement shift" above already grants the node vocabulary, exten
 to registered-blueprint references. All store I/O — label/prefix resolution, the
 `get_blueprint` fetch, the C29 doc-gate re-walk over the fetched composite (before
 it ever reaches the session, so a doc-less fetched entry cannot enter a NEW
-composition), and the resolution echo — happens CLI-side, at DTO conversion, before
+composition — a **backstop**: the register verb already gates both input forms, so
+this fires only for store content written before C29 or through the raw in-crate
+path), and the resolution echo — happens CLI-side, at DTO conversion, before
 replay; build-free introspection paths pass `&|_| None`. The echo
 (`aura: note: use "<instance>": <label-or-prefix> -> <full id>`) is the existing
 `aura: note:` benign-diagnostic marker (C14) — a new instance of the existing