Feat/horizon listener skeleton

[KingFRANKHOOD]

Add Stellar Horizon vault listener service skeleton Closes #14

Description

This PR adds a dedicated Horizon listener module in listener.ts to monitor vault contract events. It establishes the foundational pipeline for pulling, normalizing, and enqueuing Stellar events for downstream processing.

What Changed

• Listener Module: Introduced listener.ts for vault contract event monitoring.
• Network Config: Added support for Testnet and Mainnet via environment variables, including optional Horizon URL overrides.
• Processing Pipeline: Implemented a basic "Pull → Normalize → Log → Enqueue" flow.
• App Integration: Wired the listener into the main application bootstrap in index.ts, controlled by an enable flag.
• Documentation: Updated README.md with new listener-specific environment variables.

Event Subscriptions

The listener is designed to support the following vault events:

• vault_created
• validation
• release
• redirect

✅ Checklist

• Horizon listener service/module added
• Env-based network config (testnet/mainnet) added
• Contract event subscription support added
• Basic log + enqueue processing pipeline implemented
• Startup wiring integrated into app bootstrap
• Tests added for config parsing and processing pipeline

CI & Configuration Fixes

Included critical fixes to unblock CI and improve environment stability:

• package.json: Dependency/script adjustments.
• eslint.config.js: Updated linting rules.
• analytics.ts: Configuration refinements.

Validation

• New Tests: Added horizonListener.test.ts covering config parsing and pipeline logic.
• Local Run: Verified listener initializes correctly with local .env settings.

Branch

feat/horizon-vault-listener

[KingFRANKHOOD]

@1nonlypiece Please review and merge. All conflicts resolved

[1nonlypiece]

@KingFRANKHOOD Can you resolve the conflicts?

[KingFRANKHOOD]

Yes, I'll do so now