- Add DispatchNumber and CompletedDate to Dispatch model
- Add DispatchId to Comments for per-dispatch vendor threads
- GetDispatchById endpoint with vendor communication thread
- UpdateDispatch endpoint for status, NTE, dates, description
- AddDispatchComment endpoint — saves comment + sends email to vendor with sender name
- BackfillDispatchNumbers endpoint for existing dispatches
- SyncVendorReplies endpoint — pulls from DynamoDB VendorReplies table
- Fix reply-to address to include dispatch number
- Include sender name in dispatch and comment emails
