read github token from inputs

entry.ts

@@ -18,6 +18,12 @@ async function run(): Promise<void> {
   }
 
   try {
+    // Set GITHUB_TOKEN from input if provided (allows fallback to env var)
+    const githubTokenInput = core.getInput("github_token");
+    if (githubTokenInput) {
+      process.env.GITHUB_TOKEN = githubTokenInput;
+    }
+
     const inputs: Inputs = {
       prompt: core.getInput("prompt", { required: true }),
       anthropic_api_key: core.getInput("anthropic_api_key") || undefined,