perf(ci): start source feedback early and diagnose stalled runs (#3013)

* perf(ci): start source feedback early and diagnose stalled runs

* fix(ci): verify workflow identities before main comparison limits

* fix(ci): preserve diagnostics across passing checks and install failures

* fix(ci): preserve ambiguous workflow run ordering

* fix(ci): preserve failure-report candidate and request budgets

* fix(ci): retain candidate errors while checking later main evidence

* fix(ci): retain partial reports and require complete health scans

* test(ci): prune stale fixtures and duplicated assumptions

scripts/ci/github-api.mjs

@@ -0,0 +1,33 @@
+import { execFile } from "node:child_process";
+import { promisify } from "node:util";
+
+const execFileAsync = promisify(execFile);
+const MAX_BUFFER = 8 * 1024 * 1024;
+const REQUEST_TIMEOUT_MS = 10_000;
+
+/** Create a bounded GitHub CLI JSON transport with GET-only authority. */
+export function createGhApiRequest({ env = process.env, now = Date.now } = {}) {
+  return async (method, endpoint, budget) => {
+    if (method !== "GET")
+      throw new Error(
+        "GitHub API transport supports read-only GET requests only",
+      );
+    const remaining = budget.limitMs - (now() - budget.startedAt);
+    if (remaining <= 0) throw new Error("lookup_time_budget_exhausted");
+    const { stdout } = await execFileAsync(
+      "gh",
+      ["api", "--method", "GET", endpoint],
+      {
+        env,
+        encoding: "utf8",
+        maxBuffer: MAX_BUFFER,
+        timeout: Math.min(REQUEST_TIMEOUT_MS, remaining),
+      },
+    );
+    try {
+      return JSON.parse(stdout);
+    } catch (cause) {
+      throw new Error("github_api_malformed_json", { cause });
+    }
+  };
+}