chore: support Node 18 and pin @google/genai

- Relax engines to >=18.18.0\n- Pin @google/genai to 1.5.1 to avoid Node 20-only releases\n- Docs: add nvm steps and npm global prefix guidance for EACCES on Linux

README.md

@@ -60,12 +60,35 @@ g o  # AI analyzes changes, commits with perfect message, and pushes!
 
 ## 🚀 Quick Start
 
+### Prerequisites
+
+- Node.js >= 18.18.0 (Node 20+ recommended)
+- npm >= 9
+
+Tip: Use nvm to manage Node versions per-user without sudo:
+
+```bash
+curl -fsSL https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.7/install.sh | bash
+export NVM_DIR="$HOME/.nvm" && . "$NVM_DIR/nvm.sh"
+nvm install 20 && nvm alias default 20
+```
+
 ### Installation
 
 ```bash
 npm install -g gims
 ```
 
+If you get EACCES permission errors on Linux when installing globally, set a user prefix:
+
+```bash
+mkdir -p ~/.npm-global
+npm config set prefix '~/.npm-global'
+echo 'export PATH="$HOME/.npm-global/bin:$PATH"' >> ~/.bashrc
+source ~/.bashrc
+npm install -g gims
+```
+
 ### Setup AI (Choose One)
 
 **Option 1: OpenAI**

package.json

@@ -29,10 +29,10 @@
   "homepage": "https://github.com/s41r4j/gims#readme",
   "main": "bin/gims.js",
   "engines": {
-    "node": ">=20.0.0"
+    "node": ">=18.18.0"
   },
   "dependencies": {
-    "@google/genai": "^1.5.1",
+    "@google/genai": "1.5.1",
     "clipboardy": "^3.0.0",
     "commander": "^11.1.0",
     "openai": "^4.0.0",