refactor: clean up flake.nix and nixos configurations for improved readability and organization

- Reformatted `flake.nix` for better structure and consistency, including adjustments to package lists and added metadata for applications.
- Updated `nixos/gitea-runner.nix` to streamline configuration and improve clarity.
- Refined `nixos/tests.nix` by consolidating service definitions and enhancing test scripts for better maintainability and readability.

nixos/gitea-runner.nix

@@ -1,4 +1,4 @@
-{ config, pkgs, lib, ... }:
+{ pkgs, ... }:
 
 {
   # Gitea Actions Runner Configuration
@@ -6,36 +6,36 @@
 
   services.gitea-actions-runner = {
     package = pkgs.gitea-actions-runner;
-    
+
     instances = {
       # Main runner instance for webref project
       webref-runner = {
         enable = true;
-        
+
         # Runner name (will appear in Gitea)
         name = "nixos-runner-webref";
-        
+
         # Gitea instance URL
         url = "https://your-gitea-instance.com";
-        
+
         # Runner token - Generate this from Gitea:
         # Settings -> Actions -> Runners -> Create New Runner
         # Store the token in a file and reference it here
         tokenFile = "/var/secrets/gitea-runner-token";
-        
+
         # Labels define what jobs this runner can handle
         # Format: "label:docker_image" or just "label" for host execution
         labels = [
           # Native execution with Nix
           "nix:native"
-          
+
           # Ubuntu-like for compatibility
           "ubuntu-latest:docker://node:20-bookworm"
-          
+
           # Specific for this project
           "webref:native"
         ];
-        
+
         # Host packages available to the runner
         hostPackages = with pkgs; [
           # Essential tools
@@ -44,15 +44,15 @@
           curl
           git
           nix
-          
+
           # Project-specific
           nodejs
           python3
           postgresql
-          
+
           # Binary cache
           attic-client
-          
+
           # Container runtime (optional)
           docker
           docker-compose
@@ -75,16 +75,19 @@
     extraGroups = [ "docker" ];
   };
 
-  users.groups.gitea-runner = {};
+  users.groups.gitea-runner = { };
 
   # Allow runner to use Nix
   nix.settings = {
     allowed-users = [ "gitea-runner" ];
     trusted-users = [ "gitea-runner" ];
-    
+
     # Enable flakes for the runner
-    experimental-features = [ "nix-command" "flakes" ];
-    
+    experimental-features = [
+      "nix-command"
+      "flakes"
+    ];
+
     # Optimize for CI performance
     max-jobs = "auto";
     cores = 0; # Use all available cores
@@ -102,11 +105,10 @@
       # Resource limits (adjust based on your hardware)
       MemoryMax = "8G";
       CPUQuota = "400%"; # 4 cores
-      
+
       # Restart policy
       Restart = "always";
       RestartSec = "10s";
     };
   };
 }
-