Update Application Number & link for filings 2028-2031 after submission

Current Field Behavior implemented as part of this ticket:
- All three fields are editable up until the filing is submitted.
- Once submitted, fields should become read-only.
- Include guidance above the fields on the initiate budget filing Step 1: Application number and advice letter can be updated any time before you submit the budget filing.

The change would be to keep these fields editable a week after filings deadline, or the other option is always editable.

Problem it solves: SCE & PGE need to update their application ID for 2028-2031.

Gary:
We need the budget filing receipt to include in our application which we need a couple days at least ahead of actually filing the application for our case admin to properly include it in the application. But, don’t have our application number until we file. When it’s an Advice Letter like a TUAL or MCAL, our Case Admin can give it a number a couple of days earlier. Can we change the lock time frame to a day after the deadline?

Amy:
From the ED perspective, we acknowledge that it takes a few days to process application numbers (as with Decisions, Resolutions, Advice Letters, and other docs) so we do allow this time after filing to update that number and add a link to the docs.