ci: Use npm install instead of npm ci for file dependencies

The project uses @opencode-ai/plugin as a file dependency which requires
npm install to work properly in CI environments.

🤖 Generated with OpenCode

Author: rwese

.github/workflows/publish.yml

@@ -22,7 +22,7 @@ jobs:
           cache: 'npm'
 
       - name: Install dependencies
-        run: npm ci
+        run: npm install
 
       - name: Type check
         run: npm run typecheck