fix(#3121): implement commands verb in SDK native registry (#3146)

- Add commandsList handler — returns sorted JSON array of all registered
  verb strings; satisfies workstream-flag.md + agent tooling discoverability
- Register ['commands', commandsList] in DECISION_ROUTING_STATIC_CATALOG
- Add golden-policy exemption (SDK-only, no CJS mirror needed)
- check.decision-coverage-plan/verify were already registered; commands was the remaining gap

Closes #3121

sdk/src/query/command-static-catalog-foundation.ts

@@ -14,6 +14,7 @@ import { templateFill, templateSelect } from './template.js';
 import { verifySummary, verifyPathExists } from './verify.js';
 import { decisionsParse } from './decisions.js';
 import { checkDecisionCoveragePlan, checkDecisionCoverageVerify } from './check-decision-coverage.js';
+import { commandsList } from './commands-list.js';
 import { checkConfigGates } from './config-gates.js';
 import { checkAutoMode } from './check-auto-mode.js';
 import { checkPhaseReady } from './phase-ready.js';
@@ -95,4 +96,5 @@ export const DECISION_ROUTING_STATIC_CATALOG: ReadonlyArray<readonly [string, Qu
   ['check verification-status', checkVerificationStatus],
   ['check.ship-ready', checkShipReady],
   ['check ship-ready', checkShipReady],
+  ['commands', commandsList],
 ] as const;