Remove dashboard issue author display

[yvette-carlisle]

Summary

• Remove tracker issue author from the operator dashboard run metadata and debug details.
• Keep Codex account identity display on the existing alias/email privacy switch.
• Stop live run activity patches from reintroducing snapshot-only author data into the UI merge path.

Verification

• cargo +nightly fmt --all -- --check
• cargo nextest run -p decodex --all-targets --all-features operator_dashboard
• git diff --check