The type check refuses unused imports and locals: `noUnusedLocals` is on in tsconfig.json and test/ is clean #4741

Done:

• [ ] The roughly 60 findings in test/ are removed (bun x tsc --noEmit --noUnusedLocals shows none in test/), with no change to what any test asserts.
• [ ] tsconfig.json sets "noUnusedLocals": true, so bun x tsc --noEmit (the check's typecheck) fails on a new unused import. Try it once locally by adding one, then revert.
• [ ] AGENTS.md's line on the type check says unused imports and locals fail it.

Files: tsconfig.json, AGENTS.md, test/*.test.ts (decide, asks, apps-open-host, studio-shipping, quotas-running, looks and about 40 with one finding each).