Fix transport failure account locks - #24

Summary

• retry thrown connection failures twice at ten-second intervals
• preserve nested network error causes in retry and terminal logs
• never persist OAuth account/model locks for local transport failures
• advance route fallback after retries are exhausted

Validation

• npm test (321 passing)
• focused router fallback suite (41 passing)
• git diff --check

Summary by CodeRabbit

• New Features

  • Added automatic retries for temporary network failures.
  • Added fallback to alternate routes when retries are exhausted.
  • Added logging for scheduled retries and network-related failures.
  • Aborted requests now stop retrying and report client disconnection.

• Bug Fixes

  • Prevented temporary network failures from incorrectly locking provider accounts.
  • Preserved retry information during route fallback.

• Chores

  • Updated the release version to 0.5.11 and refreshed changelog links.