refactor: migrate to clean architecture with trait-based DI (v0.2.0)

Complete architectural overhaul across all 12 crates:

- Replace validator crate with zod-rs for all DTO validation
- Replace manual pagination with paginator-rs/paginator-sea-orm
- Migrate all modules (iam, cms, gacha, dimentorin) to clean architecture:
  domain → application → infrastructure layers
- Introduce trait-based DI (Arc<dyn Trait>) at every layer for repositories and services
- Delete all v1/ legacy SurrealDB-era code across every crate
- Replace opaque response helpers with typed IntoResponse structs (ApiSuccess, ApiCreated, ApiPaginated, ApiMessage)
- Remove dual_mode_repository, migration_validation_errors, validator.rs dead code
- Zero cargo clippy warnings; release build clean

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

shell.nix

@@ -1,6 +1,8 @@
-{pkgs ? import <nixpkgs> {}}:
+{
+  pkgs ? import <nixpkgs> { },
+}:
 pkgs.mkShell {
-  inputsFrom = [(pkgs.callPackage ./default.nix {})];
+  inputsFrom = [ (pkgs.callPackage ./default.nix { }) ];
   buildInputs = with pkgs; [
     rust-analyzer
     rustfmt
@@ -10,7 +12,7 @@ pkgs.mkShell {
 
     (writeScriptBin "helpme" ''
       __usage="
-      👋 Welcome to IMPHNEN CMS API development environment. 🚀
+      👋 Welcome to IMPHNEN Backend Service development environment. 🚀
       If you see this message, it means your are inside the Nix shell ❄️.
 
       [Info]===============================================================>