docs(knowledge): the judgment axis is knowledge, not a detector (B2)

Article rule 1 ("give Claude judgement instead of rules") gets its register
entry, and deliberately no detector. `BP-JUDG-001` carries `lensCheck: null`.

The cut between deterministic prefilter and prose judge was the open design
decision. It was settled by measurement, and the measurement declined both
halves:

- 409 real CLAUDE.md files (38488 lines, 8689 prose blocks): the caging class
  fires 7 times, and all 7 are false positives ("rendered prose-side",
  "naming is a flag on the class"). Verified along an independent grep path
  that bypasses block-splitting and sentence-splitting entirely, in both word
  orders: 5 lines and 1 line, none an instruction.
- The narrow variant (absolute + form noun + numeric cap) fired 8 times —
  one duplicated block seen seven times across plugin caches, precision 0 %.
  The pre-committed rule required 90 % over 20 distinct fires.
- Where the shape does occur — 45 lines across 4755 skill/agent/command files
  — it is the author's editorial policy (emoji, sentence length, slide
  titles). Nothing in the text separates that from a vendor's over-tight
  guardrail, and the article's reasoning does not transfer: the model is not
  the author of a user's config.

So no CA-OPT-002; finding-codes keeps OPT next-free = 2. The numbers live in
the entry's own `note`, so the next session does not re-derive the question.

Two premises the chunk falsified. The brief justified a separate axis by
saying these blocks sit inside `floor-exclusion`'s floor — but the article's
own canonical line carries no floor marker at all, so "inside the floor"
cannot define the axis (the corpus tendency is 76 %, which is a tendency, not
a mechanism). And the fasit's own form-noun vocabulary was wrong: `name` and
`format` alone drove 97 % of fires.

Not folded into `--subtract`: a third "loosen instead of delete" verdict in
the subtraction judge is the AS#5 mixing STATE forbids, and with the corrected
vocabulary there are 0 collisions to arbitrate anyway.

Guards, both seen red against their own defect first: the entry must exist,
be confirmed, date its source and name NO lensCheck; and every lensCheck in
the register must be backed by a real detector.

No behaviour changed — no new finding, no output change, nothing consumes the
entry yet — hence `docs`, not `feat`. Suite 1701 -> 1703/0; frozen v5.0.0 and
default-output baselines 0 changed files. Fasit:
docs/b2-judgment-lens-fasit.local.md

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017mCkx9wGywqNQzsXkBMzJ1

tests/lib/best-practices-register.test.mjs

@@ -7,6 +7,8 @@ import {
   CONFIDENCE_LEVELS,
   REGISTER_PATH,
 } from '../../scanners/lib/best-practices-register.mjs';
+import { LENS_DETECTORS } from '../../scanners/lib/lens-prefilter.mjs';
+import { SUBTRACT_DETECTORS } from '../../scanners/lib/subtraction-prefilter.mjs';
 
 // A minimal well-formed entry; negative tests clone + mutate this.
 const validEntry = () => ({
@@ -107,6 +109,56 @@ describe('bundled register integrity (Verifiseringsplikt)', () => {
       );
     }
   });
+
+  // B2. The judgment entry is knowledge WITHOUT a detector, and that is the
+  // measured outcome, not an omission: the caging class the article names fired
+  // 7 times across 409 real CLAUDE.md files and all 7 were false positives
+  // (docs/b2-judgment-lens-fasit.local.md §9.4). Asserting the absent lensCheck
+  // is what stops a later session from "completing" the entry by wiring a
+  // detector the corpus refused.
+  it('carries the judgment entry (B2) as detector-less knowledge', () => {
+    const e = getEntry(reg, 'BP-JUDG-001');
+    assert.ok(e, 'BP-JUDG-001 missing from the bundled register');
+    assert.equal(e.confidence, 'confirmed', 'BP-JUDG-001 must be confirmed');
+    assert.equal(e.category, 'judgment-fit', 'BP-JUDG-001 wrong category');
+    assert.equal(
+      e.lensCheck ?? null,
+      null,
+      'BP-JUDG-001 must NOT name a lensCheck — no detector survived measurement'
+    );
+    assert.equal(
+      e.source.url,
+      'https://claude.com/blog/the-new-rules-of-context-engineering-for-claude-5-generation-models',
+      'BP-JUDG-001 primary source must be the article that states rule 1'
+    );
+    assert.equal(e.source.published, '2026-07-24', 'BP-JUDG-001 must date its primary source');
+    assert.match(
+      String(e.note),
+      /409/,
+      'BP-JUDG-001 must carry the measured negative result, so it is not re-derived'
+    );
+  });
+
+  // The register's own consumers key on lensCheck; an entry that names one it
+  // does not have would reach a payload with no detector behind it.
+  it('every lensCheck in the register is backed by a detector', () => {
+    const detectors = new Set([
+      ...LENS_DETECTORS.map((d) => d.lensCheck),
+      ...SUBTRACT_DETECTORS.map((d) => d.lensCheck),
+      // Scanner-side checks that are their own detector.
+      'procedure-in-claude-md',
+      'CA-OST-001',
+      'CA-CML-001',
+      'CA-SKL-002',
+    ]);
+    for (const e of reg.entries) {
+      if (e.lensCheck == null) continue;
+      assert.ok(
+        detectors.has(e.lensCheck),
+        `${e.id} names lensCheck "${e.lensCheck}" with no detector behind it`
+      );
+    }
+  });
 });
 
 describe('validateRegister (negative cases)', () => {