Update job summary with progress comment content

Modified reportProgress() to write the same content to core.summary
with overwrite: true. This replaces the verbose log accumulation with
the concise progress updates that stakeholders see in comments.

The job summary now stays in sync with the progress comment,
providing a clean overview of the agent's work rather than
accumulated logs throughout execution.

Fixes #17

mcp/comment.ts

@@ -1,3 +1,4 @@
+import * as core from "@actions/core";
 import { type } from "arktype";
 import type { Payload } from "../external.ts";
 import { agentsManifest } from "../external.ts";
@@ -234,6 +235,11 @@ export async function reportProgress(
 
     progressCommentWasUpdated = true;
 
+    // update job summary with the same content as the progress comment
+    if (process.env.GITHUB_ACTIONS) {
+      await core.summary.addRaw(bodyWithFooter).write({ overwrite: true });
+    }
+
     return {
       commentId: result.data.id,
       url: result.data.html_url,
@@ -281,6 +287,11 @@ export async function reportProgress(
       body: bodyWithPlanLink,
     });
 
+    // update job summary with the same content as the progress comment
+    if (process.env.GITHUB_ACTIONS) {
+      await core.summary.addRaw(bodyWithPlanLink).write({ overwrite: true });
+    }
+
     return {
       commentId: updateResult.data.id,
       url: updateResult.data.html_url,
@@ -289,6 +300,11 @@ export async function reportProgress(
     };
   }
 
+  // update job summary with the same content as the progress comment
+  if (process.env.GITHUB_ACTIONS) {
+    await core.summary.addRaw(initialBody).write({ overwrite: true });
+  }
+
   return {
     commentId: result.data.id,
     url: result.data.html_url,