[UPSTREAM] CRITICAL: Medtrum Nano dispenses ~10U insulin during failed activation

[bcoster22]

Upstream Reference

nightscout#4594

Bug Description

CRITICAL SAFETY — At least 2 Discord users reported the Medtrum Nano pump (already on-body with needle pressed) fell back to priming stage after activation failure, dispensing ~10 units of insulin unintentionally.

Safety Impact

CRITICAL — Uncontrolled insulin delivery of ~10U can cause severe hypoglycemia and is life-threatening.

Scenario

1. User activates Medtrum Nano patch (on body, needle already pressed)
2. Activation fails for unknown reason
3. App falls back to priming stage
4. Priming dispenses ~10U of insulin through the already-inserted needle

Comments

• jbr7rr requested AAPS version info to narrow down the issue

Key Files

• pump/medtrum/ — Medtrum pump driver
• Activation state machine and priming logic
• Failure recovery/rollback code paths

Action Items

• PRIORITY: Audit Medtrum activation state machine
• Verify priming can NEVER occur when needle is already inserted
• Add state guard: if needle is deployed, block priming
• Add regression test for activation failure recovery