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

CLAUDE.md

@@ -30,7 +30,7 @@ Per-command flags, patterns, and feature lists live in `README.md` and `/config-
 |---------|-------------|
 | `/config-audit drift` | Compare current config against saved baseline |
 | `/config-audit plugin-health` | Audit plugin structure, frontmatter, cross-plugin coherence |
-| `/config-audit whats-active` | Read-only inventory of active plugins/skills/MCP/hooks/CLAUDE.md (with token estimates) |
+| `/config-audit whats-active` | Read-only inventory of active plugins/skills/agents/MCP/hooks/CLAUDE.md (with token estimates, and `model`/`effort` per agent) |
 | `/config-audit knowledge-refresh` | Refresh the best-practices register (stale check + web poll). Human-approved writes; **not byte-stable** |
 | `/config-audit campaign` | Machine-wide audit ledger + token bill across repos. Human-approved writes; **not byte-stable** |
 | `/config-audit discover` | Run discovery phase only |
@@ -79,6 +79,8 @@ Workflow: `/config-audit → discover + analyze (auto) → plan → implement
 
 Finding ID format: `CA-{SCANNER}-{NNN}` — e.g. `CA-CML-001`, `CA-SET-003`, `CA-HKV-002`, `CA-RUL-005`, `CA-TOK-005`, `CA-CPS-001`, `CA-SKL-001`, `CA-OST-001`, `CA-OPT-001`, `CA-AGT-001`.
 
+**GAP dimensions vs. levers (invariant).** `GAP_CHECKS` holds the 24 *dimensions* — always evaluated, always counted in the utilization denominators (`TIER_COUNTS` / `TOTAL_DIMENSIONS` in `scoring.mjs`, and `TITLE_TO_ID` there). A *lever* is a finding the scanner emits after the loop and only under a measured condition; it carries no tier, never enters those denominators, and is registered in the exported `LEVERS` object (code + title in one place, because the finding-code guard needs the code and the humanizer-coverage guard needs the title). Adding a dimension moves every user's utilization score and can flip the reported `segment` in a frozen baseline — adding a lever cannot. When a check is only meaningful for configs that already have some feature, it is a lever.
+
 **`{NNN}` names the CHECK, never the emission position (invariant).** `scanners/lib/finding-codes.mjs` is the single authority: every `finding()` call passes a `code`, and an undeclared or missing one **throws** — there is no counter fallback, because a fallback lets a half-converted scanner ship IDs that look valid. Adding a check takes the next free number for that scanner, never the next source-order position; removing one moves its key to `RETIRED_CODES` and its number is never reissued. IDs are therefore **not unique per finding** — one check failing in three files emits three findings sharing an ID, and `(id, file, line)` is the instance key that `fix-engine` verification uses. Frozen `v5.0.0` baselines mask IDs (`tests/helpers/mask-finding-ids.mjs`) instead of re-deriving them; the check→number pairs are pinned exhaustively in `tests/lib/finding-codes.test.mjs`.
 
 ## Conventions