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- Removed outdated plan files, consolidating failure and recovery approach in codebase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

.changeset/tricky-sites-stare.md renamed to .changeset/add-array-method-to-dsl.md

@@ -1,5 +1,5 @@
 ---
-'@pgflow/dsl': patch
+'@pgflow/dsl': minor
 ---
 
 Add `.map()` method to Flow DSL for defining map-type steps

.changeset/easy-bats-nail.md renamed to .changeset/add-map-method-to-dsl.md

@@ -1,5 +1,5 @@
 ---
-'@pgflow/core': patch
+'@pgflow/core': minor
 ---
 
 Add map step type infrastructure in SQL core