fix(lexicon,docs): retract the claim that the guard's port cites severity.mjs

The guard asked twice which file:line carried it. Tracing it produced an
uncomfortable answer: no file of ours measured it. The claim arrived from
llm-security (coord 20260809T201048Z) and was written down here as a commons
finding in three places.

Measured against the guard's own tree: severity.mjs has never appeared in
src/llm_ingestion_guard/injection_lexicon.json at any point in that file's
history (git log -S: no commits), and at 0bf0729 - the commit our manifest
pins - the only tree-wide occurrence is docs/PLAN.md:114, correctly about the
report module. Their only lexicon source statement is the note at line 3, and
it names injection-patterns.mjs. The right file.

No detection data moves. hybrid severity is still high, still sourced to
injection-patterns.mjs:274-281 at b0de0ca; severity.mjs still has zero
occurrences of the four pattern arrays, re-measured today. Only the sentence
about the other repository falls.

Marked in place, not edited away. The claim survived review because it came
bundled with a correct measurement of the same question - a wrong citation to
a right value, which is exactly what the field it lived in was written to warn
against.

lexicon/injection-lexicon.json 0.5.0 -> 0.5.1 (provenance metadata only).

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DWKkmKQBsWtrkod4MusUBC

CHANGELOG.md

@@ -9,6 +9,43 @@ Versioning note: the repository tag versions **the contract** (file set, key nam
 case ids, disposition semantics). Each JSON file additionally carries its own
 `"version"` field, bumped when that file changes.
 
+## [Unreleased]
+
+### Retracted
+
+- **The claim that the Python guard's port cites `severity.mjs` for hybrid severity.** It is
+  false. It was carried in three places — `lexicon/injection-lexicon.json`
+  (`families[hybrid].severity_provenance.not_from`), `docs/lexicon-port-divergence.md`
+  (§ *Severity: the 8 hybrid patterns*), and the `[0.1.0]` entry below — and it was never
+  measured here. It restated an assertion received from `llm-security` (coord message
+  `20260809T201048Z`) as a commons finding.
+
+  Measured against the guard's own tree, which `llm-ingestion-pipeline-security` asked for
+  twice before this was checked: `severity.mjs` has **never** appeared in
+  `src/llm_ingestion_guard/injection_lexicon.json` at any point in that file's history
+  (`git log -S` returns no commits), and at `0bf0729` — the commit
+  `conformance/manifest.json` pins — the only tree-wide occurrence is `docs/PLAN.md:114`,
+  correctly attributing the *report* module to `output.mjs` + `severity.mjs`. The guard's
+  only source statement for the lexicon is the `note` at `injection_lexicon.json:3`, and it
+  names `injection-patterns.mjs`.
+
+  **No detection data moves.** `families[hybrid].severity` is still `high`, still sourced to
+  `injection-patterns.mjs:274-281`, re-verified at `b0de0ca`; `severity.mjs` still contains
+  zero occurrences of `CRITICAL_PATTERNS`, `HIGH_PATTERNS`, `MEDIUM_PATTERNS` and
+  `HYBRID_PATTERNS`, re-measured the same day. Only the sentence about the *other* repository
+  falls.
+
+  The retraction is marked in place rather than edited away, and it is worth naming why this
+  one survived review: the claim arrived bundled with a correct measurement of the same
+  question, from a repository that had done its half properly. The correct half carried the
+  incorrect half past the check — which is precisely the defect
+  `severity_provenance.not_from` was written to warn about, one level up.
+
+### Changed
+
+- `lexicon/injection-lexicon.json` **0.5.0 → 0.5.1** — provenance metadata only; no pattern,
+  id, alias, family or severity value changes.
+
 ## [0.1.0] — 2026-08-10
 
 Initial extraction. Runtime-neutral detection data, the finding contract, and a conformance
@@ -224,6 +261,11 @@ mutation, not a weak fixture, and it is recorded as such rather than rounded up.
   `severity_provenance.not_from` records the miss explicitly: a wrong citation to a right
   value is the harder defect to catch later.
 
+  > **Correction 2026-08-10 (see Unreleased):** the two sentences about *the guard's* citation
+  > are false and were never measured here. The guard's port cites `injection-patterns.mjs`,
+  > the right file. Everything above about `severity.mjs` containing no injection-family
+  > severity, and about where the value actually lives, stands and has been re-measured.
+
   `pattern_id_space.not_yet_confirmed` is replaced by `ratification`. Both seeding runtimes
   agreed on 2026-08-09 — `llm-security` ratified the 0.2.0 proposal as-is and treats an id
   change as breaking on the same terms, and the guard confirmed the space its own port