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/create-prompt/types.ts

@@ -68,6 +68,16 @@ type IssueAssignedEvent = {
   assigneeTrigger?: string;
 };
 
+type IssueLabeledEvent = {
+  eventName: "issues";
+  eventAction: "labeled";
+  isPR: false;
+  issueNumber: string;
+  baseBranch: string;
+  claudeBranch: string;
+  labelTrigger: string;
+};
+
 type PullRequestEvent = {
   eventName: "pull_request";
   eventAction?: string; // opened, synchronize, etc.
@@ -85,6 +95,7 @@ export type EventData =
   | IssueCommentEvent
   | IssueOpenedEvent
   | IssueAssignedEvent
+  | IssueLabeledEvent
   | PullRequestEvent;
 
 // Combined type with separate eventData field