Add clear failed queue action

Add a Queue page bulk action and API route to remove all failed jobs, cover it with regression tests, and update the version, changelog, and README for the new queue workflow.

test_app.py

@@ -466,6 +466,45 @@ class QueueApiTests(unittest.TestCase):
         self.assertEqual(retried["status"], "pending")
         self.assertFalse(retried["cancel_requested"])
 
+    def test_clear_failed_removes_only_failed_jobs(self):
+        failed = self.queue.add(
+            {
+                "query": "Failed Show",
+                "title": "Failed Show",
+                "anime_name": "Failed Show",
+                "mode": "sub",
+                "quality": "best",
+                "episodes": "1",
+                "download_dir": "/tmp/example",
+                "season": "1",
+            }
+        )
+        done = self.queue.add(
+            {
+                "query": "Done Show",
+                "title": "Done Show",
+                "anime_name": "Done Show",
+                "mode": "sub",
+                "quality": "best",
+                "episodes": "1",
+                "download_dir": "/tmp/example",
+                "season": "1",
+            }
+        )
+        with self.queue.lock:
+            failed_job = self.queue._find(failed["id"])
+            failed_job["status"] = "failed"
+            self.queue._save_job_locked(failed_job)
+            done_job = self.queue._find(done["id"])
+            done_job["status"] = "done"
+            self.queue._save_job_locked(done_job)
+
+        result = self.queue.clear_failed()
+        listing = self.queue.list()
+
+        self.assertEqual(result["count"], 1)
+        self.assertEqual([job["id"] for job in listing["jobs"]], [done["id"]])
+
     def test_detach_show_clears_queue_coverage_and_sync_binding(self):
         created = self.queue.add(
             {
@@ -2817,6 +2856,33 @@ class HandlerRouteTests(unittest.TestCase):
         self.assertEqual(handler.json_status, HTTPStatus.OK)
         self.assertIn("anipy-cli", handler.json_payload)
 
+    def test_clear_failed_route_removes_failed_jobs(self):
+        with APP.DOWNLOAD_QUEUE._connect() as conn:
+            conn.execute("DELETE FROM jobs")
+        job = APP.DOWNLOAD_QUEUE.add(
+            {
+                "query": "Failed Route Show",
+                "title": "Failed Route Show",
+                "anime_name": "Failed Route Show",
+                "mode": "sub",
+                "quality": "best",
+                "episodes": "1",
+                "download_dir": "/tmp/example",
+                "season": "1",
+            }
+        )
+        with APP.DOWNLOAD_QUEUE.lock:
+            stored = APP.DOWNLOAD_QUEUE._find(job["id"])
+            stored["status"] = "failed"
+            APP.DOWNLOAD_QUEUE._save_job_locked(stored)
+
+        handler = DummyHandler("/api/queue/clear-failed", body=b"{}", content_length=2)
+        APP.Handler.do_POST(handler)
+
+        self.assertEqual(handler.json_status, HTTPStatus.OK)
+        self.assertEqual(handler.json_payload["count"], 1)
+        self.assertEqual(APP.DOWNLOAD_QUEUE.list()["total"], 0)
+
     def test_changelog_route_returns_project_changelog_content(self):
         handler = DummyHandler("/api/changelog")
         APP.Handler.do_GET(handler)
@@ -3366,6 +3432,11 @@ class TemplateHelperTests(unittest.TestCase):
     def test_search_page_sends_watchlist_auto_download_series(self):
         self.assertIn('auto_download_series: $("seasonInput").value || "1"', APP.INDEX_HTML)
 
+    def test_queue_page_includes_clear_failed_bulk_action(self):
+        self.assertIn('id="clearFailedBtn"', APP.QUEUE_HTML)
+        self.assertIn('/api/queue/clear-failed', APP.QUEUE_HTML)
+        self.assertIn('Removed failed jobs', APP.QUEUE_HTML)
+
     def test_search_page_queues_selected_title_without_result_index(self):
         self.assertIn('query: state.selected.title,', APP.INDEX_HTML)
         self.assertNotIn('index: state.selected.index,', APP.INDEX_HTML)