feat: add repository_dispatch event support

- Add new progress MCP server for reporting task status via API
- Support repository_dispatch events with task description and progress endpoint
- Introduce isDispatch flag to unify dispatch event handling
- Make GitHub data optional for dispatch events without issues/PRs
- Update prompt generation with dispatch-specific instructions

Enables triggering Claude via repository_dispatch with:
{
  "event_type": "claude_task",
  "client_payload": {
    "description": "Task description",
    "progress_endpoint": "https://api.example.com/progress"
  }
}

src/modes/types.ts

@@ -3,7 +3,7 @@ import type { PreparedContext } from "../create-prompt/types";
 import type { FetchDataResult } from "../github/data/fetcher";
 import type { Octokits } from "../github/api/client";
 
-export type ModeName = "tag" | "agent" | "experimental-review";
+export type ModeName = "tag" | "agent" | "remote-agent" | "experimental-review";
 
 export type ModeContext = {
   mode: ModeName;