mb-execute — Execution loop (plan → build → gates → verify → MB-SYNC)

• What it does: implements one scoped task and records the run in protocol files.
• Use it when: TASK-* already exists and you want a clean, resumable implementation flow.
• Input: TASK_ID plus links to the driving feature, requirement, and backlog entry.
• Output: code changes, protocol artifacts, verification inputs, and synchronized Memory Bank state.

Goal

Turn a backlog item into a reproducible, verifiable change:

• clear plan
• bounded implementation
• deterministic gates
• recorded verification
• synchronized Memory Bank