Notes the new PUT /api/routes/{id}/region endpoint as a stand-in for
the still-blocked assignAreaToRegion, and removes the stale "migration
pending" caveat now that AddRegionManagement has been applied.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
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>
DeepnaPooja