feat(scanners): model/effort routing becomes a lever, not a 25th dimension (C4)

New GAP finding CA-GAP-028: authored subagents exist and not one of them names
`model:` or `effort:`, so every delegated task runs on the main conversation's
model (`model` defaults to `inherit`). Cites BP-MODEL-001/002, landed in C1.
`whats-active` and `manifest` now carry `model`/`effort` per agent.

Shipped as a conditional LEVER rather than a 25th dimension, and the choice was
made by measurement: as a t3 dimension the agent-less marketplace-medium fixture
would count it vacuously-present, moving the denominators 41->42 and utilization
44->45 — which flips `segment` "Developing"->"Competent" in the frozen v5.0.0
posture baseline, a field strip-retired-gap.mjs does not mask. A lever never
enters those denominators. The general rule is now an invariant in CLAUDE.md.

One check across both axes, not one per axis: it fires only when neither is used
anywhere, so a deliberate everything-on-one-model policy stays silent. Cost is
recall, chosen for precision.

Found by dogfooding, fixed red-first: `model: inherit` is the documented default
spelled out, so it must not count as routing — otherwise a config opts out of the
opportunity without changing anything real.

Two pre-existing defects surfaced and closed on the way:
- The humanizer guard asserted TRANSLATIONS.GAP.static EQUALS the dimension
  titles, which forbade humanizing any lever — all three existing levers fell
  through to the generic "feature opportunity" default, wrong for a budget lever.
  Guard now requires coverage of every emittable title, seen red against those
  three before the entries were written.
- Two hand-written copies of the lever list (finding-codes guard, humanizer
  guard) merged into one exported LEVERS registry carrying code AND title.
- suppression-validation pinned CA-GAP-028 as an unoccupied number; C4 claimed
  it. Fixed structurally with a derived first-free id, not by picking a new
  literal — same class as #60's "bump this again".

Suite 1596/0. Frozen v5.0.0 snapshots untouched.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Pq3nye21RVYk4pZLeT8pGz

scanners/lib/active-config-reader.mjs

@@ -817,7 +817,7 @@ export async function enumerateRules(repoPath, pluginList = []) {
  *
  * @param {string} repoPath
  * @param {Array<{name:string, path:string}>} [pluginList]
- * @returns {Promise<Array<{name:string, source:string, pluginName:string|null, path:string, bytes:number, estimatedTokens:number, loadPattern:string, survivesCompaction:string, derivationConfidence:string}>>}
+ * @returns {Promise<Array<{name:string, source:string, pluginName:string|null, path:string, bytes:number, estimatedTokens:number, model:string|null, effort:string|null, loadPattern:string, survivesCompaction:string, derivationConfidence:string}>>}
  */
 export async function enumerateAgents(repoPath, pluginList = []) {
   const out = [];
@@ -842,6 +842,11 @@ export async function enumerateAgents(repoPath, pluginList = []) {
         path: f.path,
         bytes: f.size,
         estimatedTokens: estimateTokens(f.size, 'frontmatter'),
+        // Routing axes (C4). Explicit null rather than an absent key: `model`
+        // defaults to `inherit` and `effort` to the session level, so a consumer
+        // must be able to read "not pinned" without guessing (BP-MODEL-001/002).
+        model: hasText(frontmatter && frontmatter.model) ? frontmatter.model.trim() : null,
+        effort: hasText(frontmatter && frontmatter.effort) ? frontmatter.effort.trim() : null,
         ...lp,
       });
     }