feat(nvim): add gen.nvim and ollama service

modules/programs/nvim/plugins/coding.nix

@@ -1,4 +1,4 @@
-{ pkgs, ... }:
+{ pkgs, lib, ... }:
 
 with builtins;
 {
@@ -332,5 +332,25 @@ with builtins;
       };
       cmd = [ "Neogen" ];
     }
+    {
+      plugin = gen-nvim;
+      init = /* lua */ ''
+        require("gen").setup({
+          model = "zephyr:7b-beta", -- The default model to use.
+          display_mode = "float", -- The display mode. Can be "float" or "split".
+          show_prompt = false, -- Shows the Prompt submitted to Ollama.
+          show_model = false, -- Displays which model you are using at the beginning of your chat session.
+          no_auto_close = false, -- Never closes the window automatically.
+          init = function(options) end,
+          -- Function to initialize Ollama
+          command = "${lib.getExe pkgs.curl} --silent --no-buffer -X POST http://localhost:11434/api/generate -d $body",
+          -- The command for the Ollama service. You can use placeholders $prompt, $model and $body (shellescaped).
+          -- This can also be a lua function returning a command string, with options as the input parameter.
+          -- The executed command must return a JSON object with { response, context }
+          -- (context property is optional).
+          debug = false -- Prints errors and the command which is run.
+        })
+      '';
+    }
   ];
 }