fix: implement comprehensive failure handling and message archiving for map infrastructure

- Removed the entire PLAN.md file as the map infrastructure is complete
- Deleted the PLAN_partial_completion.md file, indicating partial recovery strategy is deprecated
- Updated documentation to reflect current failure and recovery strategies
- Enhanced failure handling to archive all pending messages on run failure
- Enforced immediate failure on type contract violations without retries
- Added detailed plan for future partial success status and clear/resume capabilities
- Clarified decision rationale for archiving messages and failing entire runs
- Updated migration and testing plans to support new failure semantics and message archiving
- Removed outdated plan files, consolidating failure and recovery approach in codebase
- Overall, this commit solidifies the failure handling, message cleanup, and recovery mechanisms
in the system

Author: jumski