Improve sources and runs history tables

tests/test_jobs.py

@@ -254,3 +254,51 @@ def test_load_runs_view_running_row_targets_queued_follow_up_cancel(
     assert running_row["cancel_post_path"] == (
         f"/actions/queued-executions/{int(pending_execution.get_id())}/cancel"
     )
+
+
+def test_load_runs_view_paginates_completed_executions_after_20_rows(
+    tmp_path: Path,
+) -> None:
+    initialize_database(tmp_path / "jobs-completed-pagination.db")
+    source = create_source(
+        name="Completed source",
+        slug="completed-source",
+        source_type="feed",
+        notes="",
+        spider_arguments="",
+        enabled=False,
+        cron_minute="*/5",
+        cron_hour="*",
+        cron_day_of_month="*",
+        cron_day_of_week="*",
+        cron_month="*",
+        feed_url="https://example.com/completed.xml",
+    )
+    job = Job.get(Job.source == source)
+    base_time = datetime(2026, 3, 30, 12, 0, tzinfo=UTC)
+    for offset in range(21):
+        JobExecution.create(
+            job=job,
+            running_status=JobExecutionStatus.SUCCEEDED,
+            ended_at=base_time - timedelta(minutes=offset),
+        )
+
+    first_page = load_runs_view(
+        log_dir=tmp_path / "out" / "logs",
+        now=base_time,
+        completed_page=1,
+    )
+    second_page = load_runs_view(
+        log_dir=tmp_path / "out" / "logs",
+        now=base_time,
+        completed_page=2,
+    )
+
+    assert len(first_page["completed"]) == 20
+    assert len(second_page["completed"]) == 1
+    assert first_page["completed_page"] == 1
+    assert second_page["completed_page"] == 2
+    assert first_page["completed_total_pages"] == 2
+    assert second_page["completed_total_pages"] == 2
+    assert first_page["completed_total_count"] == 21
+    assert second_page["completed_total_count"] == 21