feat: deep-link the logs link to the batch-filtered activity log on batch PRs

Batch PRs get their logs link back, pointing at the activity log with the
batch_pull filter (the batch's own lifecycle events) instead of the per-PR
event log. The link stays on closed batch PRs — the batch's event history is
the post-mortem trail. preset=Past1month widens the activity log's default
1-hour window, which would render empty for any batch older than an hour;
same convention as the dashboard's own queue → activity-log deep link.

MRGFY-7878

Test plan:
- npx jest (279 passing) — open batch PR (queue=batch_pr, logs=batch_pull),
  closed batch PR (logs only), non-batch PRs keep the per-PR event-log link.
- npx biome check — clean.

Depends-On: Mergifyio/monorepo#36623
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QyefSTmdtUKXCSbYRJvSQu
Change-Id: I5c6a720156143892c507ecfc3921f14c400a5b8b

Author: JulianMaurin

src/__tests__/queue.test.js

@@ -901,32 +901,40 @@ describe("batch-PR informational links", () => {
             .map((a) => a.textContent.trim())
             .filter((t) => t === "queue" || t === "logs");
     }
-    function queueHrefOf(row) {
+    function hrefOf(row, label) {
         return [...row.querySelectorAll("a")]
-            .find((a) => a.textContent.trim() === "queue")
+            .find((a) => a.textContent.trim() === label)
             ?.getAttribute("href");
     }
 
-    test("open batch PR: queue link deep-links via batch_pr, no logs link", () => {
+    const BATCH_ACTIVITY_LOG_HREF =
+        "https://dashboard.mergify.com/activity-log?login=acme&repository=widget&batch_pull=42&preset=Past1month";
+
+    test("open batch PR: queue link deep-links via batch_pr, logs link via batch_pull", () => {
         setPrDom({ draft: true, author: "mergify", baseRef: "develop" });
         const row = buildMergifyRow();
-        expect(linkLabels(row)).toEqual(["queue"]);
-        expect(queueHrefOf(row)).toBe(
+        expect(linkLabels(row)).toEqual(["queue", "logs"]);
+        expect(hrefOf(row, "queue")).toBe(
             "https://dashboard.mergify.com/queues/status?login=acme&repository=widget&branch=develop&batch_pr=42",
         );
+        expect(hrefOf(row, "logs")).toBe(BATCH_ACTIVITY_LOG_HREF);
     });
 
-    test("closed batch PR: no queue link and no logs link", () => {
+    test("closed batch PR: no queue link, logs link via batch_pull", () => {
         setPrDom({ closed: true, author: "mergify" });
         const row = buildMergifyRow();
-        expect(linkLabels(row)).toEqual([]);
+        expect(linkLabels(row)).toEqual(["logs"]);
+        expect(hrefOf(row, "logs")).toBe(BATCH_ACTIVITY_LOG_HREF);
     });
 
-    test("open non-batch PR keeps both the queue and logs links", () => {
+    test("open non-batch PR keeps both the queue and per-PR event-log links", () => {
         setPrDom({ author: "octocat", baseRef: "develop" });
         const row = buildMergifyRow();
         expect(linkLabels(row)).toEqual(["queue", "logs"]);
-        expect(queueHrefOf(row)).toContain("pull-request-number=42");
+        expect(hrefOf(row, "queue")).toContain("pull-request-number=42");
+        expect(hrefOf(row, "logs")).toBe(
+            "https://dashboard.mergify.com/event-logs?login=acme&repository=widget&pullRequestNumber=42",
+        );
     });
 
     test("closed human PR is unaffected — keeps both links", () => {

src/queue.js

@@ -535,23 +535,43 @@ function appendCommandButtons(container) {
 // Append the queue and logs links via the caller's appendLink(href, text, svg),
 // honoring batch-PR restrictions: the queue link points at the batch peek
 // drawer while the batch PR is open and is dropped once it closes (the batch
-// has drained — nothing to open); the logs link is omitted on batch PRs
-// entirely (not supported for batches yet).
+// has drained — nothing to open); the logs link points at the batch-filtered
+// activity log on batch PRs — kept on closed ones, where the batch's event
+// history is the post-mortem trail.
 function appendBatchAwareLinks(appendLink) {
     const batch = isBatchPrContext();
     if (!batch || isPullRequestOpen()) {
         appendLink(getMergeQueueLink(), "queue", QUEUE_ICON_SVG);
     }
-    if (!batch) {
-        appendLink(getEventLogLink(), "logs", LOGS_ICON_SVG);
-    }
+    appendLink(
+        batch ? getBatchActivityLogLink() : getEventLogLink(),
+        "logs",
+        LOGS_ICON_SVG,
+    );
 }
 
 export function getEventLogLink() {
     const data = getPullRequestData();
     return `https://dashboard.mergify.com/event-logs?login=${data.org}&repository=${data.repo}&pullRequestNumber=${data.pull}`;
 }
 
+// Activity log pivoted to a batch's own lifecycle events via its batch_pull
+// filter — a batch PR has no per-PR event log, so this replaces
+// getEventLogLink() on batch PRs. preset=Past1month widens the page's default
+// 1-hour window, which would render empty for any batch older than an hour
+// (a drained batch's post-mortem being the main use); same convention as the
+// dashboard's own queue → activity-log deep link.
+export function getBatchActivityLogLink() {
+    const data = getPullRequestData();
+    const params = new URLSearchParams({
+        login: data.org,
+        repository: data.repo,
+        batch_pull: data.pull,
+        preset: "Past1month",
+    });
+    return `https://dashboard.mergify.com/activity-log?${params}`;
+}
+
 // Base branch of the current PR, read from the classic PR UI. The
 // `.commit-ref.base-ref` span is titled "owner/repo:branch"; ref names can't
 // contain ":", so everything after the first colon is the branch (which may