fix(external-plugins): preserve cards during intake

Include submissions awaiting review or submitter fixes in the review board feed so refreshes preserve their existing state. Keep fast-track and approval gated on a ready intake state, and add regression coverage for card persistence across pending transitions.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 821f4796-505e-4fb8-96cf-0b5bbf80a636

.github/extensions/external-plugin-review-board/lib/github.test.mjs

@@ -0,0 +1,21 @@
+import assert from "node:assert/strict";
+import { test } from "node:test";
+
+import { mapBoardIssues } from "./github.mjs";
+
+test("board feed includes submissions in each active intake state", () => {
+    const issues = ["ready-for-review", "awaiting-review", "requires-submitter-fixes", "rejected"].map(
+        (state, index) => ({
+            number: index + 1,
+            title: `Submission ${index + 1}`,
+            author: { login: "contributor" },
+            labels: [{ name: "external-plugin" }, { name: state }],
+            url: `https://github.com/github/awesome-copilot/issues/${index + 1}`,
+        }),
+    );
+
+    assert.deepEqual(
+        mapBoardIssues(issues).map((issue) => issue.number),
+        [1, 2, 3],
+    );
+});