Add exact MMS file-transfer failure diagnostics

[masarray]

Field problem

Fault-record discovery succeeds and the remote CFG/DAT/INF bundle is complete, but Download still ends in a generic InvalidDataException. The application currently loses the primary failing request because the best-effort FileClose can overwrite the shared last-request/last-response fields.

Changes

• capture a bounded per-transfer protocol timeline
• preserve the first/primary failure even when cleanup also fails
• report stage, remote path, invoke ID, signed FRSM, FileRead number, bytes transferred, moreFollows, exception type/message, association/pump state, pending confirmed operations, receive routing, pump fault, and compact request/response hex
• distinguish FileOpen, each FileRead, local write/flush, validation, FileClose, timeout, and skipped-close failures
• embed the full trace in fault-record bundle failure results
• keep the trace bounded to avoid retaining file payloads or unbounded history

This instrumentation is designed to make the next field result decisive before any packet-capture comparison is required.

[chatgpt-codex-connector]

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