Unify with v2 client

[josh-chamberlain]

Context

• Follows/originally part of Q4 2024 overhaul #184

Requirements

• merge the data-sources-app client and homepage into this repo's dev branch
• update the https://pdap.io homepage's search section to be the new v2 search
  • remove links and references to v1, https://data-sources.pdap.io

Our homepage will be the product, with deeper pages available:

• pdap.io/ (map, search, homepage stuff)
  • pdap.io/results
  • /about
  • /donate
  • /etc