fix: enforce strict schema for debug workflow tester

[haosenwang1018]

Summary

• enable strictSchema: true for the tester agent in debug-workflow
• add a template resolver regression test that locks this behavior in

Related Issues

Fixes #458

Changes Made

• update cluster-templates/base-templates/debug-workflow.json so the tester keeps native CLI schema enforcement instead of falling back to post-validation over stream-json
• add coverage in tests/template-resolver.test.js to assert the resolved tester agent preserves strictSchema: true

Testing

• ./node_modules/.bin/mocha tests/template-resolver.test.js tests/type-safety-validation.test.js

Checklist

• Tests pass (npm test)
• Documentation updated (if needed)
• Follows commit guidelines

[tomdps]

Status review (2026-07-29):

• Current main already fixes tester agent JSON schema validation always fails in stream-json mode #458 generally: validateAgentConfig/applyStrictSchemaDefault defaults unset agents to strict schema while preserving the global strictSchema=false opt-out; resolveOutputFormatConfig keeps JSON and buildTaskRunArgs forwards --json-schema, while buildFinalContext supplies the schema for the explicit stream fallback.
• This PR is GitHub-mergeable but behind main, has no reported checks, and is not merge-ready: adding strictSchema: true to the debug-workflow tester would override that supported global opt-out, and its new test would lock in the conflicting behavior (cluster-templates/base-templates/debug-workflow.json; tests/settings.test.js).
• The linked issue is closed as fixed; this patch is superseded and should not be merged as written.