chore: Resolve duplicate migration timestamps (20260416100000 vs 20260416120000)

[MatthewSuttles]

Context

Merged via PR #246 (Task Layer). Two migrations landed on main with overlapping timestamps from the same day:

• 20260416100000
• 20260416120000

These both target task-layer schema changes and could cause ordering issues or conflicts depending on the runner.

Action

• Audit both migration files for overlap or redundancy
• If they touch the same tables/columns, consolidate into a single migration
• If they are independent, re-timestamp one to ensure deterministic ordering
• Verify db:migrate runs cleanly from scratch and idempotently

Origin

Follow-up from PR #246 admin merge.