Add CHAIN DIGITAL testnet validator info

[chaindigital]

Added CHAIN DIGITAL validator metadata to testnet folder.

Validator ID: 219
Website: https://chaindigital.tech/

[greptile-apps]

Greptile Summary

Added validator metadata for CHAIN DIGITAL (ID: 219) to the testnet directory. The submission follows the required format with all mandatory fields present and properly structured.

• Filename matches the SECP public key as required
• All fields conform to the schema (id, name, secp, bls, website, description, logo, x)
• URLs use HTTPS protocol
• Public keys are in correct format (66-char SECP, 96-char BLS)
• GitHub Actions will verify logo accessibility and on-chain key matching

Confidence Score: 5/5

• This PR is safe to merge with minimal risk
• The submission is a straightforward validator metadata addition that follows all documented requirements and repository conventions. The file structure matches the schema, filename convention is correct, and all required fields are present with appropriate data types. GitHub Actions will perform automated validation of logo accessibility and on-chain key verification.
• No files require special attention

Important Files Changed

Filename	Overview
testnet/02cc4fe99c47c438b17fadac0da4bdf2d643ca6c19ce140d6ca7233f00b200a048.json	Added CHAIN DIGITAL validator metadata with all required fields properly formatted

_{Last reviewed commit: 988893b}