change from mono-home-manager to full flake multi-system configuration

home/llm.nix

@@ -0,0 +1,67 @@
+{ config, pkgs, lib, ... }:
+
+let
+  ollamaModelDir = "/mnt/models/ollama"; # ✅ change to your external disk or large partition
+  modelsToInstall = [
+    "llama3"
+    "mistral"
+    "codellama"
+    "gemma"
+  ];
+  cfg = config.homeModules.llm;
+in
+
+lib.mkIf cfg.enable {
+  home.packages = with pkgs; [
+    ollama
+    opencode
+  ];
+
+  # Set up environment variables
+  home.sessionVariables = {
+    OLLAMA_MODELS = ollamaModelDir;
+    OLLAMA_HOST = "127.0.0.1:11434";
+  };
+
+  # Systemd user service for ollama daemon
+  systemd.user.services.ollama = {
+    Unit = {
+      Description = "Ollama LLM Inference Daemon";
+      After = [ "network.target" ];
+    };
+
+    Service = {
+      ExecStart = "${pkgs.ollama}/bin/ollama serve";
+      Environment = [
+        "OLLAMA_MODELS=${ollamaModelDir}"
+        "OLLAMA_HOST=127.0.0.1:11434"
+      ];
+      Restart = "on-failure";
+    };
+
+    Install = {
+      WantedBy = [ "default.target" ];
+    };
+  };
+
+  # Setup ollama models via activation script
+  home.activation.installOllamaModels = lib.hm.dag.entryAfter [ "writeBoundary" ] ''
+    export OLLAMA_MODELS=${ollamaModelDir}
+    export OLLAMA_HOST=127.0.0.1:11434
+
+    mkdir -p ${ollamaModelDir}
+
+    echo "⏳ Checking and pulling ollama models..."
+    for model in ${builtins.toString modelsToInstall}; do
+      if ! ${pkgs.ollama}/bin/ollama list | grep -q "$model"; then
+        ${pkgs.ollama}/bin/ollama pull "$model"
+      fi
+    done
+  '';
+
+  # Optional aliases for quick usage
+  programs.zsh.shellAliases = {
+    llm = "opencode";
+    ollama-ui = "xdg-open http://localhost:11434";
+  };
+}