build: add bazel rust workflow

flake.nix

@@ -55,12 +55,14 @@
       inputs.nixpkgs.follows = "nixpkgs";
     };
 
+    # TODO: deprecate / remove
     # Agent-ergonomic CLI for Gitea, with a home-manager module for the agent context.
     gitea-axi = {
       url = "git+https://git.alexion.dev/alexion/gitea-axi";
       inputs.nixpkgs.follows = "nixpkgs";
     };
 
+    # TODO: deprecate / remove
     # Personal agent skills, packaged as per-skill derivations with a home-manager module.
     skills = {
       url = "git+https://git.alexion.dev/alexion/skills";
@@ -75,7 +77,30 @@
 
   outputs =
     { self, nixpkgs, ... }@inputs:
+    let
+      system = "x86_64-linux";
+      pkgs = nixpkgs.legacyPackages.${system};
+
+      pkgsDefault = [ pkgs.bazel ];
+      pkgsRust = with pkgs; [
+        cargo
+        clippy
+        rust-analyzer
+        rustc
+        rustfmt
+      ];
+
+      mkShell = packages:
+        pkgs.mkShell {
+          packages = pkgsDefault ++ packages;
+        };
+    in
     {
+      devShells.${system} = {
+        default = mkShell [ ];
+        rust = mkShell pkgsRust;
+      };
+
       nixosConfigurations = (import ./src/dotfiles {
         inherit inputs self;
         lib = nixpkgs.lib;