Validation/Event Model & Persistence

[Adedayo-Data]

Closes #3

---

Overview

This PR implements the data model and repository layer for validation events. These events are necessary to record milestone validation actions and vault lifecycle transitions.

Changes Made Include:

Database Migrations

1. Created the validations table with the following schema:

• id: (Primary Key, varchar 64)
• vault_id: (Foreign Key referencing vaults)
• milestone_id: (Nullable Foreign Key referencing milestones)
• validator_user_id: (Varchar/UUID)
• action: (Enum: validated, failed, cancelled, extended)
• metadata: (JSONB)
• tx_hash: (varchar 128)
• created_at: (Timestamp)

2. Types & Entities
   Established TypeScript interfaces for ValidationEvent and CreateValidationEventDto alongside the ValidationAction union type.

3. Repository Layer
   Implemented ValidationRepository with basic CRUD support utilizing Dependency Injection for the Knex instance.

Testing

• Added unit tests verifying persistence and queries through dependency-injected mock chaining.
• All unit tests are currently passing (npm run test).

[1nonlypiece]

@Adedayo-Data Can you resolve the conflicts?

[Adedayo-Data]

Would work on it...