fix(pull-request): prioritize failed checks

apps/server/src/pullRequest/bitbucketPullRequestJson.test.ts

@@ -328,8 +328,8 @@ describe("decodeStatusesJson", () => {
     );
 
     expect(decoded.items.map((check) => [check.name, check.status])).toEqual([
-      ["build / Pipeline", "success"],
       ["deploy / Pipeline", "failure"],
+      ["build / Pipeline", "success"],
     ]);
   });
 });

apps/server/src/pullRequest/gitHubPullRequestJson.test.ts

@@ -234,8 +234,8 @@ describe("pull request detail decoding", () => {
   it("maps check-run status and commit-status state onto one vocabulary", () => {
     const detail = expectSuccess(decodePullRequestDetailJson(detailJson));
     expect(detail.checks.map((check) => [check.name, check.status])).toEqual([
-      ["build", "pending"],
       ["test", "failure"],
+      ["build", "pending"],
       ["ci/legacy", "success"],
     ]);
   });

apps/server/src/pullRequest/pullRequestChecks.test.ts

@@ -50,6 +50,24 @@ describe("dedupeChecks", () => {
     ]);
   });
 
+  it("puts failed and cancelled checks first without reshuffling either group", () => {
+    const checks = dedupeChecks([
+      entry("lint", "success"),
+      entry("unit", "failure"),
+      entry("types", "pending"),
+      entry("integration", "cancelled"),
+      entry("format", "success"),
+    ]);
+
+    expect(checks.map((check) => [check.name, check.status])).toEqual([
+      ["unit", "failure"],
+      ["integration", "cancelled"],
+      ["lint", "success"],
+      ["types", "pending"],
+      ["format", "success"],
+    ]);
+  });
+
   it("loses a run that never said when it happened to one that did, whichever came first", () => {
     const undated = dedupeChecks([
       entry("build", "success", { at: "2026-08-11T16:00:00Z" }),
@@ -76,8 +94,8 @@ describe("dedupeChecks", () => {
     ]);
 
     expect(checks.map((check) => [check.name, check.status])).toEqual([
-      ["CI / build", "success"],
       ["Release / build", "failure"],
+      ["CI / build", "success"],
     ]);
   });
 
@@ -88,6 +106,6 @@ describe("dedupeChecks", () => {
       entry("build", "failure", { workflowName: "CI", at: "2026-08-11T16:00:00Z" }),
     ]);
 
-    expect(checks.map((check) => check.name)).toEqual(["build", "CI / build"]);
+    expect(checks.map((check) => check.name)).toEqual(["CI / build", "build"]);
   });
 });

apps/server/src/pullRequest/pullRequestChecks.ts

@@ -19,8 +19,9 @@ function isAtLeastAsNew(candidate: string | null, kept: string | null): boolean
  * one before it, and a run that never said when it happened loses to one that did. A tie goes to
  * whichever came last, because a host lists a re-run after the run it repeats.
  *
- * The order is the host's own, held at the place each check first appeared, so a re-run landing
- * mid-read replaces a row where it stands instead of reshuffling the list under the reader.
+ * Failed and cancelled checks come first so the reason for a failing rollup is immediately visible.
+ * Within that group and the remaining checks, the order is the host's own, held at the place each
+ * check first appeared. A re-run landing mid-read replaces a row where it stands.
  *
  * Two checks that survive under the same name are then genuinely different ones, since they came
  * from different workflows — each is shown as `workflow / name`, the way GitHub writes it itself.
@@ -46,10 +47,17 @@ export function dedupeChecks(
   for (const entry of survivors) {
     countsByName.set(entry.check.name, (countsByName.get(entry.check.name) ?? 0) + 1);
   }
-  return survivors.map((entry) => {
+  const checks = survivors.map((entry) => {
     const workflowName = entry.workflowName ?? "";
     return workflowName.length > 0 && (countsByName.get(entry.check.name) ?? 0) > 1
       ? { ...entry.check, name: `${workflowName} / ${entry.check.name}` }
       : entry.check;
   });
+  const failing = checks.filter(
+    (check) => check.status === "failure" || check.status === "cancelled",
+  );
+  return [
+    ...failing,
+    ...checks.filter((check) => check.status !== "failure" && check.status !== "cancelled"),
+  ];
 }