added separate aichat role

roles/home/aichat.nix

@@ -0,0 +1,34 @@
+{ pkgs, ... }:
+let
+  aichatConfigDir = "$HOME/.config/aichat";
+  aichatConfig = ''
+    model: ollama
+    clients:
+    - type: ollama
+      api_base: https://ollama.giugl.io
+      api_key: null
+      models:
+      - name: pino
+        max_input_tokens: null    
+      - name: code-commenter
+        max_input_tokens: null    
+      - name: git-commit-message
+        max_input_tokens: null
+        
+    - type: claude
+      api_key: null
+
+    - type: openai
+      api_key: null
+      api_base: https://api.openai.com/v1
+  '';
+in
+{
+  home = {
+    sessionVariables = {
+      AICHAT_CONFIG_DIR = aichatConfigDir;
+    };
+    packages = [ pkgs.unstablePkgs.aichat ];
+    file.".config/aichat/config.yaml".text = aichatConfig;
+  };
+}