Roadmap: keep screenshots and release package fresh

[YfengJ]

Goal

Keep the public repository homepage and release package aligned with the current system UI.

Tasks

• Refresh sanitized screenshots after visible UI changes.
• Rebuild dist/course-system-release.zip before public handoff.
• Re-run privacy scans for README images, sample data, and release contents.

Acceptance Criteria

• README screenshots match the latest stable UI.
• Release package excludes runtime data, databases, uploads, exports, backups, real course files, and secrets.

[YfengJ]

Maintenance audit on 2026-06-30: regenerated the sanitized release package, reran local tests and compile checks, scanned the archive for private runtime data and key-like strings, and added Dependabot maintenance checks in commit 133076a.