[JFWooten4]

Summary

• replace Horizon REST account lookups with Stellar RPC getLedgerEntries reads of the classic account ledger entry
• derive the master signer weight, additional Ed25519 signer weights, low/medium/high thresholds, and lastModifiedLedgerSeq directly from the RPC XDR response
• rename the server integration from horizon.ts to rpc.ts and update error handling and UI terminology accordingly
• switch deployment configuration from HORIZON_URL to STELLAR_RPC_URL, defaulting to https://mainnet.sorobanrpc.com
• fully rewrite the README around the current architecture, RPC configuration, proof semantics, deployment, persistence, and trust model
• remove the personal signer-name example from the README, UI placeholder, and tests

Why

Signer weight and threshold data are ledger state. Reading the account ledger entry through Stellar RPC keeps authority verification on the RPC path used by current Stellar infrastructure while preserving the existing SEP-53 proof format and the application's own REST API.

The signed authority snapshot still includes the account entry's last-modified ledger sequence, so the submission-time recheck continues to reject signatures if signer weights or thresholds changed after review.

Validation

• verified the generated tree differs from main
• verified src/server/horizon.ts is removed and src/server/rpc.ts is present
• verified the RPC implementation calls getLedgerEntries
• verified the README contains the new STELLAR_RPC_URL configuration and does not contain the removed personal signer name
• verified the UI and server entry point no longer contain Horizon terminology