Modernize Bitcoin ElectrumX GUI and runtime

[RyleaStark]

Summary

• modernize the Bitcoin ElectrumX GUI/backend facade with React, TypeScript, Fastify, and typed contracts
• derive provider progress from private ElectrumX admin heights, validate required Bitcoin Core indexes separately, and require a successful public Electrum query before ready
• pin a maintained ElectrumX 2.0.0 runtime source revision with separated private-admin/public-wallet listeners
• preserve ElectrumX/Bitcoin product identity, legacy routes, and suffix-free host:port wallet details with SSL None
• leave the upstream GitHub Actions workflows unchanged

Validation

• npm ci
• npm audit --audit-level=low (0 vulnerabilities)
• npm run audit:production (0 vulnerabilities)
• npm run lint
• npm run typecheck
• npm test (64/64)
• npm run test:coverage (64/64)
• npm run build
• docker compose config -q
• git diff --check upstream/master...HEAD

No tag, release, or OCI image was published.

blocks getumbrel/umbrel-apps#5976

[RyleaStark]

sync-to-complete.mp4

[RyleaStark]

Reversed github actions changes, looks like we had some collusion.