fix(api): clean up stale waiting tasks

[vavo]

What does this pull request do. Explain your changes. (required)

Fixes #1670 by cleaning up tasks that remain in the waiting phase indefinitely and preventing new tasks from being added when a user has reached the pending-task limit.

Specific updates (required)

• Add a task-cleanup job for first-attempt tasks stuck in waiting for more than six hours.
• Mark stale tasks as failed through the existing scheduler failure path.
• Update related output assets and preserve existing task and asset webhook behavior.
• Protect cleanup updates with an allowed-phase check so a concurrent task result cannot be overwritten.
• Enforce queue capacity for scheduler-created tasks.
• Add configurable task-cleanup and task-cleanup-limit CLI options.
• Add focused tests for cleanup behavior and job registration.

How did you test each of these updates (required)

• Prettier validation.
• API TypeScript check.
• Focused cleanup and job tests under Node 22.
• Scheduler/database integration tests with real Postgres and RabbitMQ services.
• Full API source test suite: 506 tests passed.

The repository-wide Jest command also discovers generated dist tests. Those artifact tests fail because generated schema files are not available in dist; the source test suite passes.

Does this pull request close any open issues?

Fixes #1670

Screenshots (optional)

Not applicable.

Checklist

• I have read the CONTRIBUTING document.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.

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Project	Deployment	Actions	Updated (UTC)
livepeer-studio	Error		Jul 30, 2026 10:30pm

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[vavo]

Hey guys, this is my first PR for your repo. Although I've read your documentation on contributing , PR template and Code of Conduct, detailed feedback on what did I miss, what to do better, etc is more than welcome.

Also if there is a specific issue(s) you'd like to help with, let me know, I can have a look. Thanks!