feat(profiles): DEFAULT stamps commons' O2 generated, V1 executed

Commons ratified V1 2026-08-02 and executed it at `54e0ec7`; verified
against their tree rather than taken on report. ingest-spec.md:217 now
defines `generated` as `{ by: process:okf-ingest, at: <ingested_at> }`,
unquoted, `at` repeating `ingested_at` verbatim. `generated: true` no
longer appears in the spec.

`DEFAULT` states commons' §5 layer, so its stamp is theirs to decide.
`DEFAULT.ownership` gains the actor; the four goldens this repo's plan
named in advance were regenerated by RUNNING the materializer, each on
its own case's `ingested-at.txt`. The v0.2 golden was untouched, as
predicted -- it has carried the O2 form since D5.

Not a migration onto OKF v0.2: `DEFAULT` stays v0.1 on every axis
upstream owns and still emits no `sources`. Commons' spec and the Google
version are independent axes, and comments that narrated them as one
were rewritten rather than left to mislead. README and CLAUDE.md said
the additive rule without that boundary, which would have told a
consumer their DEFAULT bytes can never move; both now state it.

V-A3 is amended, not dropped. `DEFAULT` must OWN the mapping it now
writes -- a profile refusing its own output fires the collision gate on
files its own previous run wrote -- while a mapping naming a foreign
actor, or §7's `human:` actor on curated content, stays unowned. That
half is what carried the safety and it is asserted directly.

§11's stamp-integrity condition moved with the value: the forgeable
stamp was `true` and is now the mapping naming the ingest actor. The
defence was never the value -- the §3 scan globs `ingest-*.md`, so a
Door C import is unreachable however well it forges. Second spoof test
added; both were hand-mutated (glob widened to `*.md`) to confirm they
can fail.

The characterization test derived its foreign-stamp fixture from the
literal `generated: true`, which V1 leaves without a referent -- a
silent no-op waiting to happen. It now derives the needle from the
profile and asserts the substitution occurred.

Door B is deliberately untouched: not the ingest-spec's, marker is
`generated` + `source_file`, disjoint from Door A's `ingest_manifest`,
and the divergence predates V1.

Nothing released or notified. The pilot set pins `v0.5.0a2`, not `main`,
so this is invisible to portfolio-optimiser's freeze and demo; the
consumer exposure report is owed at the release that carries this.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VwcjUXbKySLbEG5WqTNkta

tests/test_profile_threading.py

@@ -106,7 +106,9 @@ def test_default_run_is_unchanged_by_the_new_parameter(file_setup: tuple[Path, P
     materialize_bundle(manifest_path, explicit_dir, INGESTED_AT, profile=DEFAULT)
     assert (explicit_dir / "ingest-orders.md").read_bytes() == implicit
     assert (explicit_dir / "index.md").read_bytes() == index_implicit
-    assert b"generated: true" in implicit
+    # Not redundant with the equality above: it pins WHICH profile the implicit
+    # run used. Without it the two calls could agree while both being wrong.
+    assert f"generated: {{ by: process:okf-ingest, at: {INGESTED_AT} }}".encode() in implicit
 
 
 def test_profile_is_keyword_only(file_setup: tuple[Path, Path]) -> None: