landing page updates

[whoabuddy]

We can create sub-issues if needed.

• [x] remove sparkles and gradient
• [x] remove "AIBTC Crew Generator" text
• [x] remove gray box/background, keep button
• [x] bigger, bolder button text, simplify to "Connect Wallet"
• [x] status text should not shift layout
  • [x] probably eliminated if we remove the box
  • [x] could explore using toast instead: "sign up complete / sign in complete"
• [x] handle no wallet found with toast (covered in #5)

[whoabuddy]

Fixed in #21