feat: add audit and fix mode to recommended maintenance runs

[atomantic]

Summary

Add an Audit mode selector to the recommended maintenance sequence in Scheduled Tasks. Audit and fix runs each improvement task with issue filing disabled, then performs one final perpetual claim-issue drain after documentation. File issues remains the default, with the existing drains between audits.

The launch API validates the mode and the shared step builder stores the chosen sequence, so saved runs retain their behavior when resumed. Switching modes clears launch consent.

Test plan

• Server maintenance workflow and schedule route tests: 55 passed, including fix-mode ordering, final drain repetition/completion, default compatibility, and invalid mode rejection.
• Client maintenance form, Schedule tab, and quota task catalog tests: 33 passed, including mode selection and renewed consent.
• Maintenance, quota dispatch, and sequence tests: 48 passed.
• Production client build passed.