Simplify review found that force_refresh=True on every validate_transaction()
call caused redundant API fetches on every embed render and button press.
Instead, invalidate the roster cache after successful submit_transaction() so
the next operation fetches fresh data. This preserves the cache for normal
interaction flows while still preventing stale data after submissions.
Also adds type annotation for roster_svc DI parameter.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
TransactionBuilder cached roster data indefinitely via _roster_loaded flag,
causing validation to use stale counts when builders persisted across multiple
/ilmove invocations. Now validate_transaction() always fetches fresh roster
data. Also adds dependency injection for roster_service to improve testability.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
