fix(e2e): Add missing mock routes and resolve TODOs

Adds mock route handlers for `/api/stats/history`, `/api/event_ids`,
and `/api/*/latest.webp` to the Playwright test configuration
(`api-mocker.ts`). Fixes the `sub_labels` test regression by adjusting
the mock route registration order. Removes corresponding resolved
TODO comments from the E2E error allowlist (`error-allowlist.ts`).

Co-authored-by: manupawickramasinghe <73810867+manupawickramasinghe@users.noreply.github.com>

Author: google-labs-jules[bot]

web/e2e/fixtures/error-allowlist.ts

@@ -56,29 +56,6 @@ export const GLOBAL_ALLOWLIST: RegExp[] = [
   // Fix: add route handlers for /api/review and /api/review/** in api-mocker.ts.
   /500 Internal Server Error.*\/api\/review(\?|\/|$)/,
 
-  // TODO(real-bug): /api/stats/history is not mocked; the system page fetches
-  // it for the detector/process history charts.
-  // Fix: add route handler for /api/stats/history in api-mocker.ts.
-  /500 Internal Server Error.*\/api\/stats\/history/,
-
-  // TODO(real-bug): /api/event_ids is not mocked; the explore/search page
-  // fetches it to resolve event IDs for display.
-  // Fix: add route handler for /api/event_ids in api-mocker.ts.
-  /500 Internal Server Error.*\/api\/event_ids/,
-
-  // TODO(real-bug): /api/sub_labels?split_joined=1 returns 500; the mock
-  // registers "**/api/sub_labels" which may not match when a query string is
-  // present, or route registration order causes the catch-all to win first.
-  // Fix: change the mock route to "**/api/sub_labels**" in api-mocker.ts.
-  /500 Internal Server Error.*\/api\/sub_labels/,
-
-  // TODO(real-bug): MediaMocker handles /api/*/latest.jpg but the app also
-  // requests /api/*/latest.webp (webp format) for camera snapshots.
-  // Affects: live.spec.ts, review.spec.ts, auth.spec.ts, navigation.spec.ts.
-  // Fix: add route handler for /api/*/latest.webp in MediaMocker.install().
-  /500 Internal Server Error.*\/api\/[^/]+\/latest\.webp/,
-  /failed: net::ERR_ABORTED.*\/api\/[^/]+\/latest\.webp/,
-
   // -------------------------------------------------------------------------
   // Mock infrastructure gap — WebSocket streams.
   //

web/e2e/helpers/api-mocker.ts

@@ -81,6 +81,9 @@ export class ApiMocker {
     await this.page.route("**/api/stats", (route) =>
       route.fulfill({ json: stats }),
     );
+    await this.page.route("**/api/stats/history**", (route) =>
+      route.fulfill({ json: [] }),
+    );
 
     // Reviews. The real backend exposes /review (singular) for the main
     // list and /review/summary for the summary — the previous plural glob
@@ -113,11 +116,7 @@ export class ApiMocker {
       route.fulfill({ json: [] }),
     );
 
-    // Sub-labels and attributes (for explore filters).
-    // Use trailing ** so query-string variants (e.g. ?split_joined=1) match.
-    await this.page.route("**/api/sub_labels**", (route) =>
-      route.fulfill({ json: [] }),
-    );
+
     await this.page.route("**/api/labels**", (route) =>
       route.fulfill({ json: ["person", "car"] }),
     );
@@ -129,6 +128,9 @@ export class ApiMocker {
     );
 
     // Events / search
+    await this.page.route("**/api/event_ids**", (route) =>
+      route.fulfill({ json: [] }),
+    );
     await this.page.route("**/api/events**", (route) =>
       route.fulfill({ json: events }),
     );
@@ -222,6 +224,12 @@ export class ApiMocker {
       // Fall through to more specific routes for GET requests
       return route.fallback();
     });
+
+    // Sub-labels and attributes (for explore filters).
+    // Use trailing ** so query-string variants (e.g. ?split_joined=1) match.
+    await this.page.route("**/api/sub_labels**", (route) =>
+      route.fulfill({ json: [] }),
+    );
   }
 }
 
@@ -234,6 +242,12 @@ export class MediaMocker {
 
   async install() {
     // Camera snapshots
+    await this.page.route("**/api/*/latest.webp**", (route) =>
+      route.fulfill({
+        contentType: "image/webp",
+        body: PLACEHOLDER_PNG,
+      }),
+    );
     await this.page.route("**/api/*/latest.jpg**", (route) =>
       route.fulfill({
         contentType: "image/png",