[IOS-IMAP-015] Fix the SwiftMail pipelined FETCH promise leak in debug tests

[tabmail-kmyi]

Current status

Open; explicitly deferred in the current register.

This is the live GitHub tracker for IOS-IMAP-015. The canonical technical record contains the evidence, scope, constraints, accepted recovery behavior, and fix direction:

• Companion/Process/Current/KnownIssues/Amendments/ios-imap-015.md

Completion

• Implement and verify the remedy described in the canonical record.
• Update the canonical record with the final disposition and proof.
• Close this issue only when the record is resolved or the owner explicitly accepts it as a limitation.