Add resolution validation checks to plan validate

Acceptance Criteria

• Info-level check: work/bug items with status done/fixed but no ## Resolution section
• Warning-level check: items with a ## Resolution section but status is not done/fixed
• Warning-level check: files with multiple ## Resolution headings
• All three checks appear in plan validate output with correct severity levels
• Unit tests cover each check

Approach

Add a checkResolutions() function in runes/plan/src/commands/validate.ts. This depends on the scanner exposing resolution data (WORK-071), so the checks can use entity.resolution to determine presence. Alternatively, the validator could do its own raw-text scan of the file for ## Resolution headings to avoid depending on the scanner change — simpler but slightly redundant.

References

• Work Item Resolution Summaries
• Lumina Per-Rune Redundant CSS Cleanup — scanner resolution parsing (dependency)

Resolution

Completed: 2026-03-30

All three resolution checks implemented in runes/plan/src/commands/validate.ts with checkResolutions() function. Five unit tests cover each check type. All criteria verified met.