* feat(ui): add budget duration to edit team member form
Editing a team member created a member budget with no duration, so the
budget never reset. This threads a budget reset period through the edit
flow end to end and reuses the shared duration dropdown so the options
stay in sync with the rest of the UI.
Resolves LIT-2651
* fix(proxy): validate member budget_duration and persist clears
Reject budget_duration values that can't be parsed, are non-positive, or overflow date math before any write, so a bad value can't be persisted and later crash the budget reset job.
Clearing the budget duration in the edit-member form now sends null and clears the column end to end, so the dropdown's clear control reflects a real change instead of being a no-op
* chore(ui): regenerate schema.d.ts for member budget_duration
Adds budget_duration to TeamMemberUpdateRequest/Response in the generated dashboard types so the Check UI API Types Sync gate passes
