Define and implement Founding Member cutoff date

[bokelley]

Context

From Slack conversation in #aao-admin:

• Unity asked to be shown as a "Founding Member" when they join
• Brian confirmed this should apply to anyone joining before April
• Need to transition from "Founding Member" designation to regular member list around Jan 15

Requirements

1. Define clear cutoff date for "Founding Member" status (suggested: ~Jan 15 or before April?)
2. Update member list/directory to show Founding Member badge/designation
3. Switch to regular member list display after cutoff
4. Document the criteria in membership docs

Questions

• Exact cutoff date: Jan 15, end of January, or April 1? (website will show original logos until Jan 15, then we'll use the member list. Founding member pricing available through March 31)
• Should Founding Members get any ongoing distinction on the website? (yes)
• Does this apply to all membership tiers or just corporate? (only corporate)