feat: add backend for distribution

[Chesblaw]

Feature: Distributions Backend

This PR introduces a complete backend implementation for the Distributions system, enabling batch badge distributions, persistent storage, and retrieval endpoints.

✨ New Features

Batch Distribution Endpoint

• Each user maintains an independent, on-chain ScoreProfile.

• New REST endpoint::

POST /distributions

Query Capabilities

• Retrieve all items for a given distribution:

GET /distributions/:distributionId

Technical Implementation

• Rust + SQLx Backend
• PostgreSQL storage

Files Added

src/application/commands/create_distribution.rs
distribution_dto.rs
src/domain/entities/distribution.rs
src/domain/repositories/distribution_repository.rs
src/infrastructure/repositories/postgres_distribution_repository.rs
migrations/4_add_distributions.sql

Files Modified

Backend router/handler to wire distribution endpoints

Usage Example

{
  "items": [
    {
      "address": "0xAbc123...",
      "badge_name": "EarlyContributor",
      "metadata": { "campaign": "beta" }
    }
  ],
  "metadata": { "triggered_by": "system" }
}

✅ Checklist

• Rust compilation passes
• SQLx compile-time checks validated
• Database migrations run cleanly
• Endpoints tested and functional
• Domain models aligned with schema

[joelamouche]

Thanks for the submission @Chesblaw ! Overall looks great, even though I would need to dig deeper into the implementation details.

However, before I do that, I think that something wasn't clear when in the task description: the distribution id is know before registering it into our backend (and therefore you should generate it in our backend).

The flow goes this way:

1. create list of users that should get batches
2. distribute badges to user using (foundry) script: this is where the distribution id is created (and optionally registered onchain to avoid duplicate distribution)
3. register distirbution in the backend for accountability

Thanks in advance!

[Chesblaw]

@joelamouche gotchu

[joelamouche]

@Chesblaw How's the task going?

[joelamouche]

Any progress on this @Chesblaw ? Would be a shame to throw away a great PR

[Chesblaw]

Hey @joelamouche i'm sorry for the late i will update you within a few days.

[joelamouche]

Okay sounds good :)

[tusharshah21]

Any update mate @Chesblaw?