fix(cicd-squabbler-mcp): review follow-ups — copyright line, diagnose shape tolerance (#81)

## Summary

Two confirmed findings from the multi-angle review of the Push #2 change
set, applied to the just-merged `cicd-squabbler-mcp` cartridge (#80):
the README gains the estate copyright line (every merged sibling ci-cd
README carries it on line 2 — SPDX alone lacks attribution), and
`squabble_diagnose` now accepts both the documented bare `{checks}`
shape and the `{gate:{checks}}` wrapper callers generalise from
`squabble_fight` by analogy (previously an opaque 400; the
`squabble-app` backend tolerates both as of cicd-squabbler#14). One
cartridge, one PR.

## Schema-validation note

- [ ] This PR adds or modifies one or more `cartridge.json` manifests.
- [x] This PR does not touch any `cartridge.json`.

(`README.adoc` + `mod.js` only; the manifest is untouched, so the strict
gate's baseline is unaffected. `schemas/PINNED-SHA` untouched.)

## Refs

- Review + backend counterpart: hyperpolymath/cicd-squabbler#14 (same
review sweep; backend shape tolerance landed there)
- Original cartridge: #80
- Note for the owner: commits from this environment are **unsigned** —
needs owner signing per CONTRIBUTING.

---
_Generated by [Claude
Code](https://claude.ai/code/session_01SUURnQUnzTXYftzWFs5pfZ)_

Co-authored-by: Claude <noreply@anthropic.com>

Author: hyperpolymath

cartridges/domains/ci-cd/cicd-squabbler-mcp/README.adoc

@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: CC-BY-SA-4.0
+// Copyright (c) 2026 Jonathan D.A. Jewell (hyperpolymath) <j.d.a.jewell@open.ac.uk>
 = cicd-squabbler-mcp
 
 CI/CD gate-fighter cartridge — makes

cartridges/domains/ci-cd/cicd-squabbler-mcp/mod.js

@@ -44,11 +44,13 @@ export async function handleTool(toolName, args) {
       return post("/api/v1/fight", payload);
     }
     case "squabble_diagnose": {
-      const { checks } = args ?? {};
+      // Accept both the documented bare shape ({checks}) and the
+      // gate-wrapped shape ({gate:{checks}}) callers generalise from
+      // squabble_fight by analogy — the backend tolerates both too.
+      const checks = args?.checks ?? args?.gate?.checks;
       if (!Array.isArray(checks)) {
-        return { status: 400, data: { error: "checks (array) is required" } };
+        return { status: 400, data: { error: "checks (array) is required — pass {checks:[...]} or {gate:{checks:[...]}}" } };
       }
-      // The backend takes the Gate object directly.
       return post("/api/v1/diagnose", { checks });
     }
     default: