Add label trigger functionality to Claude Code Action (#177)

- introduced a new input parameter `label_trigger` in `action.yml` to allow triggering actions based on specific labels applied to issues.
- Enhanced the context preparation and event handling in the code to support the new labled event.

src/github/validation/trigger.ts

@@ -13,7 +13,7 @@ import type { ParsedGitHubContext } from "../context";
 
 export function checkContainsTrigger(context: ParsedGitHubContext): boolean {
   const {
-    inputs: { assigneeTrigger, triggerPhrase, directPrompt },
+    inputs: { assigneeTrigger, labelTrigger, triggerPhrase, directPrompt },
   } = context;
 
   // If direct prompt is provided, always trigger
@@ -34,6 +34,16 @@ export function checkContainsTrigger(context: ParsedGitHubContext): boolean {
     }
   }
 
+  // Check for label trigger
+  if (isIssuesEvent(context) && context.eventAction === "labeled") {
+    const labelName = (context.payload as any).label?.name || "";
+
+    if (labelTrigger && labelName === labelTrigger) {
+      console.log(`Issue labeled with trigger label '${labelTrigger}'`);
+      return true;
+    }
+  }
+
   // Check for issue body and title trigger on issue creation
   if (isIssuesEvent(context) && context.eventAction === "opened") {
     const issueBody = context.payload.issue.body || "";