Add FIFO Scenario scheduling

frontend/e2e/scenario-history.spec.ts

@@ -1,6 +1,8 @@
 import { expect, test, type Page } from "@playwright/test";
 
 const RUN_ID = "123e4567-e89b-12d3-a456-426614174000";
+const ACTIVE_RUN_ID = "123e4567-e89b-12d3-a456-426614174001";
+const QUEUED_RUN_ID = "123e4567-e89b-12d3-a456-426614174002";
 const ATTACK_ID = "attack-result-1";
 const SCENARIO_NAME = "airt.jailbreak";
 const RAW_IMAGE_HTML = '<img src=x onerror="alert(1)">unsafe';
@@ -697,4 +699,146 @@ test.describe("Scenario catalog, history, and live run routing", () => {
     expect((await refresh.boundingBox())?.height).toBeGreaterThanOrEqual(44);
     expect((await row.boundingBox())?.height).toBeGreaterThanOrEqual(44);
   });
+
+  test("renders deterministic FIFO position changes and queued-to-completed handoff", async ({ page }) => {
+    await mockScenarioAPIs(page);
+    let progressRequests = 0;
+    let queueRequests = 0;
+    let releasePositionOne: () => void = () => {};
+    let releaseInProgress: () => void = () => {};
+    let releaseCompleted: () => void = () => {};
+    const positionOneGate = new Promise<void>((resolve) => {
+      releasePositionOne = resolve;
+    });
+    const inProgressGate = new Promise<void>((resolve) => {
+      releaseInProgress = resolve;
+    });
+    const completedGate = new Promise<void>((resolve) => {
+      releaseCompleted = resolve;
+    });
+
+    await page.route(new RegExp(`/api/scenarios/runs/${QUEUED_RUN_ID}/progress(?:\\?|$)`), async (route) => {
+      progressRequests += 1;
+      const gate = [undefined, positionOneGate, inProgressGate, completedGate][progressRequests - 1];
+      if (gate) {
+        await gate;
+      }
+      const statuses = ["QUEUED", "QUEUED", "IN_PROGRESS", "COMPLETED"] as const;
+      const status = statuses[Math.min(progressRequests - 1, statuses.length - 1)];
+      const queuePosition = status === "QUEUED" ? (progressRequests === 1 ? 2 : 1) : null;
+      await route.fulfill({
+        status: 200,
+        contentType: "application/json",
+        body: JSON.stringify({
+          run: {
+            ...runSummary,
+            scenario_result_id: QUEUED_RUN_ID,
+            status,
+            completed_at: status === "COMPLETED" ? runSummary.completed_at : null,
+            queue_position: queuePosition,
+            active_scenario_result_id: status === "QUEUED" ? ACTIVE_RUN_ID : QUEUED_RUN_ID,
+            overload_summaries: [{
+              component_role: "objective_target",
+              count: 2,
+              rate_limit_count: 1,
+              server_error_count: 1,
+              status_codes: [429, 503],
+              latest_timestamp: "2026-08-07T00:00:45Z",
+            }],
+          },
+          plan: progressRequests === 1 ? plan : null,
+          summary: {
+            overall: {
+              completed: status === "COMPLETED" ? 1 : 0,
+              planned: 1,
+              succeeded: status === "COMPLETED" ? 1 : 0,
+              success_percentage: status === "COMPLETED" ? 100 : null,
+              errors: 0,
+              retries: 0,
+            },
+            display_groups: [],
+            techniques: [],
+            seed_groups: [],
+            atomic_groups: [],
+            unattributed_attempts: 0,
+          },
+          reset: progressRequests === 1,
+          active_atomic_group_ids: status === "IN_PROGRESS" ? ["group-1"] : [],
+          results: status === "COMPLETED" ? [progressAttempt] : [],
+          next_cursor: `queue-progress-${progressRequests}`,
+          has_more: false,
+          plan_complete: true,
+        }),
+      });
+    });
+
+    await page.route(/\/api\/scenarios\/runs\/queue(?:\?|$)/, async (route) => {
+      queueRequests += 1;
+      const active = {
+        scenario_result_id: ACTIVE_RUN_ID,
+        scenario_name: "Active scenario",
+        scenario_registry_name: "active.scenario",
+        state: "IN_PROGRESS",
+        created_at: "2026-08-07T00:00:00Z",
+        enqueued_at: "2026-08-07T00:00:00Z",
+        started_at: "2026-08-07T00:00:01Z",
+      };
+      const queued = {
+        scenario_result_id: QUEUED_RUN_ID,
+        scenario_name: "Jailbreak",
+        scenario_registry_name: SCENARIO_NAME,
+        state: "QUEUED",
+        position: queueRequests === 1 ? 2 : 1,
+        created_at: runSummary.created_at,
+        enqueued_at: runSummary.created_at,
+      };
+      await route.fulfill({
+        status: 200,
+        contentType: "application/json",
+        body: JSON.stringify({
+          revision: queueRequests,
+          snapshot_at: `2026-08-07T00:00:0${Math.min(queueRequests, 9)}Z`,
+          active: queueRequests < 3 ? active : queueRequests === 3 ? { ...queued, state: "IN_PROGRESS", position: null } : null,
+          queued: queueRequests < 3
+            ? [
+                ...(queueRequests === 1 ? [{ ...queued, scenario_result_id: RUN_ID, position: 1 }] : []),
+                queued,
+              ]
+            : [],
+        }),
+      });
+    });
+
+    await page.goto(`/scanner-history/${QUEUED_RUN_ID}`);
+
+    try {
+      await expect(page.getByTestId("run-state-badge")).toHaveText("Queued");
+      await expect(page.getByTestId("queued-run-progress")).toContainText("Position 2");
+      await expect(page.getByTestId("queued-run-progress")).not.toContainText("%");
+      await expect(page.getByRole("link", { name: new RegExp(ACTIVE_RUN_ID) })).toHaveAttribute(
+        "href",
+        `/scanner-history/${ACTIVE_RUN_ID}`,
+      );
+      const warning = page.getByTestId("scenario-overload-warning");
+      await expect(warning).toContainText("Objective target");
+      await expect(warning).toContainText("2 × HTTP 429/503");
+      await expect(warning).toContainText("without adaptive throttling");
+      await page.setViewportSize({ width: 390, height: 844 });
+      expect((await page.getByRole("button", { name: "Cancel run" }).boundingBox())?.height).toBeGreaterThanOrEqual(44);
+
+      releasePositionOne();
+      await expect(page.getByTestId("queued-run-progress")).toContainText("Position 1");
+      releaseInProgress();
+      await expect(page.getByTestId("run-state-badge")).toHaveText("In progress");
+      releaseCompleted();
+      await expect(page.getByTestId("run-state-badge")).toHaveText("Completed");
+      expect(progressRequests).toBe(4);
+
+      expect(await page.evaluate(() => document.documentElement.scrollWidth)).toBeLessThanOrEqual(390);
+    } finally {
+      releasePositionOne();
+      releaseInProgress();
+      releaseCompleted();
+    }
+  });
 });

frontend/e2e/themes.spec.ts

@@ -40,6 +40,12 @@ const API_RESPONSES: Record<string, unknown> = {
   '/api/converters/catalog': { items: [] },
   '/api/scenarios/catalog': EMPTY_PAGE,
   '/api/scenarios/runs': EMPTY_PAGE,
+  '/api/scenarios/runs/queue': {
+    revision: 0,
+    snapshot_at: '2026-01-01T00:00:00Z',
+    active: null,
+    queued: [],
+  },
   '/api/config': { content: 'initializers: []\n', source: 'theme-preview', version: '1' },
   '/api/config/env-files': { items: [] },
   '/api/initializers': EMPTY_PAGE,