* feat(billing): introduce unified subscription price increase scheduler API
* feat(billing): implement unified subscription price increase scheduler logic
* refactor(billing): update subscription handlers to use unified scheduler
* feat(billing): extend price migration feature flag checks
* test(billing): add and update tests for unified price increase scheduler
* fix(billing): run dotnet format
* feat(billing): expand customer and customer.discount on subscription fetch
* refactor(ReinstateSubscriptionCommandTests): rename test method for broader scope
* feat(billing): expand customer.discount in update handler
* test(billing): update test name
* feat(billing): add test clock waiting mechanism for upcoming invoices
* feat(billing): introduce cancelling user ID metadata key
* feat(billing): store cancelling user ID on subscription cancellation
* feat(billing): clear cancelling user ID on subscription reinstatement
* test(billing): update subscriber service tests for cancelling user ID
* style(SubscriberService): use 'is not null' pattern matching
* feat(SubscriberService): add PM35215 migration cohort metadata handling
* feat(SubscriberService): extend price migration deferral to PM35215
* test(SubscriberService): add and update tests for PM35215 feature
* feat(billing): Introduce OrganizationPriceIncreaseOptions
* refactor(billing): Centralize price increase eligibility in scheduler
* refactor(billing): Delegate price increase validation from UpcomingInvoiceHandler
* feat(billing): Manage price increase schedules during subscription lifecycle events
* test(billing): Update UpcomingInvoiceHandlerTests for centralized validation
* test(billing): Add PriceIncreaseScheduler tests for SkipIfAlreadyScheduled option
* test(billing): Add SubscriberService tests for price increase schedule management
* fix(billing): run dotnet format
* fix(billing): remove redundant customer expansion
* fix(billing): expand discounts for customer and subscription
* refactor(billing): Rename method to clarify dispatching role for organization scheduling
* fix(billing): Prevent clearing migration cohort metadata on cancellation
* fix(billing): Fallback to standard email when price increase migration fails
* feat(billing): improve observability for missing migration path data
* refactor(billing): simplify business plan type identification
* [PM-37064] feat: Add ScheduleBusinessPriceIncrease scheduler entry point
Extends PriceIncreaseScheduler (PM-32645) with a parallel entry point for
Teams/Enterprise 2020 → current plan migrations under epic PM-35215. The
business path consumes a cohort directly, preserves existing discounts,
optionally appends the cohort's proactive coupon, and stamps ScheduledDate
on the assignment row on success.
Existing Schedule renames to SchedulePersonalPriceIncrease across four
call sites; ResolvePhase2Async becomes private. Shared concerns extract
into ActiveScheduleExistsAsync and CreateAndConfigureScheduleAsync helpers.
ScheduleBusinessPriceIncrease has zero production callers — the
UpcomingInvoiceHandler dispatcher branch lands in a follow-up. The new
PM35215_BusinessPlanPriceMigration feature flag defaults off.
* Address PR review: prevent orphan schedules and fix Release flag gate
