Reduce react-hooks/set-state-in-effect warnings below budget #646

Context

eslint-plugin-react-hooks v7 introduced react-hooks/set-state-in-effect through the recommended preset. The repository currently keeps this rule at warn in node/eslint.config.js because several effects synchronize local state with persistence, context hydration, and job-status polling.

The ESLint hook uses a warning budget in node/scripts/run-eslint-hook.sh. The current baseline is 31 warnings across 24 files. The budget has been raised from 30 to 50 to keep CI usable while this is addressed.

Goal

Refactor legitimate cases and remove unnecessary synchronous state updates inside effects so the warning count returns below the original budget of 30, without disabling the rule.

Acceptance criteria

• react-hooks/set-state-in-effect remains enabled as a warning.
• The warning count is below 30.
• Existing persistence, hydration, polling, and user-selection behavior remains unchanged.
• Node lint and the relevant frontend tests pass.