Create release plan for early adopters migration

# Release Plan Notes

Early Adopter Release Checklist : https://docs.google.com/spreadsheets/d/1MLarh3fR4vc5Ub9sMBEbLpt_YHb7JhkAQlkw55rvGbs/edit?gid=0#gid=0

## Assumptions:
- Home team has made necessary updates to support early adopters corps being frozen and the correct messaging in legacy search to inform users these corps are available in modernized system
- Early adopter teams channel(s) will be setup so we can communicate with clients around issues that may come up
- Account have been created in modernized system that we will use to affiliate corps

## Steps
**Can we do steps 1 & 2 the day before the migration?**
1. Freeze early adopter corps in COLIN(can we do this the day before the migration?)
2. Extract latest COLIN prod data
3. Run tombstone pipeline to migrate early adopter corps to LEAR prod db.
4. Verify migrated data in LEAR prod db.
* All early adopter corps were migrated
* Data verification for a few corps ensuring all expected tombstone data brought over and tombstone data looks correct
5. Verify from UI perspective. Note this will be only UI level verification
* Able to load businesses
* Filing ledger items match what is in Corporate Online
* Business summary is hidden
* etc
6. Verify new filings made in modernized system sync back to COLIN. We will need to monitor early adopter corps on fixed interval or get early adopters to inform us when they do new filings.

Start with the Early Adopter Release Checklist linked in the issue and review the assumptions and migration steps. Confirm the timing of the freeze and data extraction, then document ownership and completion criteria for database, UI, and filing-sync verification so the release plan is actionable.

Written by the indexing model from the issue text.