Kobe API: Add blacklist field

[aoikurokawa]

No description provided.

[Copilot]

Pull Request Overview

This PR adds support for tracking Jito blacklist status for validators by integrating with the Steward Config account. The implementation fetches the validator blacklist from the on-chain Steward Config and exposes this information through the API.

• Adds is_jito_blacklist field to track validator blacklist status
• Integrates Steward Config account fetching for both mainnet and testnet
• Removes unused jito_tip_distribution_sdk module in favor of the workspace dependency

Reviewed Changes

Copilot reviewed 6 out of 7 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
core/src/fetcher.rs	Adds Steward Config fetching and blacklist status logic; removes inline SDK module
core/src/db_models/validators.rs	Adds is_jito_blacklist field to Validator model
core/src/constants.rs	Defines Steward Config addresses for mainnet and testnet
core/Cargo.toml	Adds jito-tip-distribution-sdk workspace dependency
api/src/schemas/validator.rs	Exposes is_jito_blacklist field in API response schema
api/src/resolvers/query_resolver.rs	Maps is_jito_blacklist field in query responses

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