Backend rewrite to rust for more preformance

[Chace-Berry]

feat(backend): rewrite Alterion panel backend to Rust (SeaORM + Actix Web)

TODO: Complete backend rewrite from [current stack] to Rust

Core Setup

• Initialize new Rust workspace with Cargo.toml
• Add dependencies: actix-web, sea-orm, tokio, serde, dotenv, tracing
• Configure async runtime (Tokio) and logging (tracing-subscriber)
• Set up .env / config loading (envy or config crate)

Database Layer (SeaORM)

• Define SeaORM entities for all existing models
• Write and test initial migrations (sea-orm-cli migrate)
• Implement repository pattern / data access layer
• Set up connection pooling (SeaORM + SQLx pool)
• Validate all relations (one-to-many, many-to-many, etc.)

API Layer (Actix Web)

• Scaffold Actix Web app with modular router structure
• Port all existing REST endpoints to Actix handlers
• Implement request/response DTOs with serde
• Add input validation (validator crate)
• Wire up middleware: auth, CORS, rate limiting, logging

Authentication

• Implement JWT auth middleware (jsonwebtoken crate)
• Port session/token management logic
• Role-based access control (RBAC) guards

Error Handling

• Define unified AppError enum (thiserror)
• Implement actix ResponseError for AppError
• Standardize error response format (JSON)

Testing

• Unit tests for service/business logic layer
• Integration tests for all API routes (actix-web test client)
• Seed test database via SeaORM fixtures

DevOps / Deployment

• Update Dockerfile for Rust multi-stage build
• Update CI/CD pipeline for cargo build/test
• Verify feature parity with old backend before cutover
• Update API docs / OpenAPI spec (utoipa or paperclip)

BREAKING CHANGE: full backend replacement — verify all panel API consumers