fix: stop requeueing worked issues

[jeremymcs]

Summary

• prevent automatic issue work from requeueing issues already marked as worked
• skip worked issues in the automatic evaluation sweep too
• add regression coverage for both duplicate work and duplicate evaluation paths

Verification

• npm run test -- server/appRuntime.test.ts
• npm run check
• /simplify server/appRuntime.ts server/appRuntime.test.ts

[github-actions]

📄 Documentation Review Reminder

This PR changes source files but does not update any public documentation.

Changed source files:

server/appRuntime.test.ts
server/appRuntime.ts

Please check if documentation in docs/public/ needs to be updated:

• No documentation update needed
• Documentation updated in this PR
• Follow-up documentation issue created

Public docs are Markdown files in docs/public/. They are automatically
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Available docs: getting-started.md, pr-babysitter.md, agent-dispatch.md, configuration.md, pr-questions.md