Workflow tasks cleaner

Overview

This is a maintenance release focused on WCAG 2.1 AA accessibility for the admin UI and hardening of the cleanup scheduler backend. No new features, no breaking changes; the GraphQL schema and module configuration surface are unchanged.

Highlights

• Full WCAG 2.1 AA pass on the React admin UI (Scheduler Configuration + Workflow Tasks Cleaner panels).
• Race-condition fix on the manual/scheduled cleanup trigger.
• Server-side validation of the cron expression before persistence.

Changes

Backend — WorkflowTasksCleanerMutationExtension.java

• Race guard hardening (runClean): replaced the non-atomic get() + set() pattern with AtomicBoolean.compareAndSet(false, true), closing the TOCTOU window where two concurrent invocations (manual GraphQL trigger + scheduler tick) could both start a cleanup pass.
• Cron validation (saveConfig): the submitted cronExpression is now validated via org.quartz.CronExpression.isValidExpression(...) before being persisted. Previously an admin could save a syntactically invalid schedule that would silently fail to activate at the next scheduler bind.

Frontend — Accessibility (WCAG 2.1 AA)

Affected files:

• src/javascript/WorkflowTasksCleaner/WorkflowTasksCleaner.jsx
• src/javascript/WorkflowTasksCleaner/SchedulerConfig.jsx
• src/javascript/WorkflowTasksCleaner/WorkflowTasksCleaner.scss
• src/main/resources/javascript/locales/en.json (new label.scheduler.configTitle)

Critical fixes:

• CRIT-01 — Table header font size raised from 0.6875rem to 0.75rem to remain legible at the uppercase scale.
• CRIT-02 — The single dynamic-role live region was split into two fixed-role, always-in-DOM regions (role="status" + role="alert") in both panels. Removed the liveRef focus call that was moving focus to a visually hidden element.
• CRIT-03 — Tables switched from aria-label to aria-labelledby pointing to an existing on-screen heading, avoiding Moonstone child-forwarding ambiguity.

Major fixes:

• MAJ-01 — Hardcoded #595959 for table header, tooltip and restart-hint text (replaces var(--color-gray) whose Moonstone runtime value could fall below the 5.5:1 contrast threshold).
• MAJ-02 — Hardcoded #767676 for section and table-row borders (previous #dadada failed SC 1.4.11 non-text contrast at 1.47:1).
• MAJ-03 / MIN-08 — SchedulerConfig document.title and <h2> now use label.scheduler.configTitle ("Scheduler Configuration") instead of a generic "Configuration".
• MAJ-04 — Module-level .wtc_container *:focus-visible policy added (2px accent outline) for keyboard focus visibility.
• MAJ-05 — .wtc_label label font-size converted from 14px to 0.875rem (SC 1.4.4 — text resizing).
• MAJ-06 — Cron Input now carries required + aria-required="true" (SC 3.3.2, 4.1.2).
• MAJ-07 — Cron Input exposes aria-invalid and a conditional aria-describedby referencing wtc-cron-error on save failure (SC 3.3.1).

Upgrade Notes

• Drop-in replacement for 2.0.0. No JCR, OSGi config, or GraphQL contract changes.
• Existing persisted cron expressions are not re-validated retroactively; only new/edited values pass through the new validator.
• Operators relying on the previous behaviour where invalid cron strings could be saved should expect a GraphQL error on save in 2.0.1.

Full Changelog: 2_0_0...2_0_1