8b84c8aeb3
Updates mainPlan.md's Region Management table, 10_region_management.md's status/open-questions/implementation-notes sections, and BACKEND_API_REFERENCE.md's Regions section to reflect the newly added target/budget/agency-map/tax-rule/hierarchy/dashboard endpoints, and flags that the EF Core migration for the new tables is still pending. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>