[FEATURE] Add scheduled recurring scans with blackout windows

[utksh1]

Problem

SecuScan needs a production-grade improvement in this area: Recurring scan automation..

Scope

Support cron-like schedules, timezone handling, blackout windows, missed-run policy, and UI management.

Acceptance Criteria

• The implementation is focused and does not introduce unrelated UI, docs, lockfile, or formatting churn.
• Security-sensitive behavior has explicit negative tests where applicable.
• Existing tests continue to pass, and new tests cover the main success and failure paths.
• Documentation or configuration examples are updated when operator behavior changes.

Verification

Tests should cover timezone boundaries, blackout skips, missed run recovery, and disabled schedules.

Difficulty

Hard, useful issue intended for experienced contributors.

[YerraguntaAjayKumar]

Hi @utksh1, I am a GSSoC '26 contributor and would love to take on this critical issue to implement scheduled recurring scans with blackout windows!

Here is my proposed implementation plan:

1. Backend & DevOps: - Implement a robust cron-like scheduling service with robust timezone evaluation.
   • Design a blackout window validation check that intercepts and defers or skips scheduled jobs dynamically.
   • Build a missed-run recovery policy to handle system downtime safely without duplicate task execution.
2. Frontend UI:
   • Create a clean React form/interface within the tool configuration to allow operators to easily input cron expressions, define timezone boundaries, and configure blackout time-ranges.
3. Quality & Security:
   • Write explicit unit tests covering edge-case timezone boundaries, skipped blackout intervals, and disabled schedules.
   • Ensure the implementation is highly focused, keeping clean lockfiles and preventing any lint/formatting churn.

If this plan looks solid, please assign this issue to me!