fix(jina-reader): recover after transient errors and use JSON POST API

Clear stale provider error code and account lock after a successful web
fetch (the core fetch handler never consumed the onRequestSuccess
callback), switch Jina Reader to its documented JSON POST request, and
parse the Title: metadata line before falling back to a Markdown heading.

tests/unit/fetch-success-clears-account.test.js

@@ -0,0 +1,91 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+
+const mocks = vi.hoisted(() => ({
+  getProviderCredentials: vi.fn(),
+  markAccountUnavailable: vi.fn(),
+  clearAccountError: vi.fn(),
+  extractApiKey: vi.fn(() => null),
+  isValidApiKey: vi.fn(),
+  getSettings: vi.fn(),
+  getCombos: vi.fn(),
+  handleFetchCore: vi.fn(),
+  checkAndRefreshToken: vi.fn(),
+}));
+
+vi.mock("@/sse/services/auth.js", () => ({
+  getProviderCredentials: mocks.getProviderCredentials,
+  markAccountUnavailable: mocks.markAccountUnavailable,
+  clearAccountError: mocks.clearAccountError,
+  extractApiKey: mocks.extractApiKey,
+  isValidApiKey: mocks.isValidApiKey,
+}));
+
+vi.mock("@/lib/localDb", () => ({
+  getSettings: mocks.getSettings,
+  getCombos: mocks.getCombos,
+}));
+
+vi.mock("open-sse/handlers/fetch/index.js", () => ({
+  handleFetchCore: mocks.handleFetchCore,
+}));
+
+vi.mock("@/sse/services/tokenRefresh.js", () => ({
+  checkAndRefreshToken: mocks.checkAndRefreshToken,
+  updateProviderCredentials: vi.fn(),
+}));
+
+vi.mock("@/sse/utils/logger.js", () => ({
+  request: vi.fn(),
+  info: vi.fn(),
+  debug: vi.fn(),
+  warn: vi.fn(),
+  error: vi.fn(),
+  maskKey: vi.fn(() => "masked"),
+}));
+
+vi.mock("@/shared/utils/ssrfGuard.js", () => ({
+  assertPublicUrl: vi.fn(),
+}));
+
+import { handleFetch } from "@/sse/handlers/fetch.js";
+
+describe("web fetch account state", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    mocks.getSettings.mockResolvedValue({ requireApiKey: false });
+    mocks.getCombos.mockResolvedValue([]);
+    mocks.getProviderCredentials.mockResolvedValue({
+      apiKey: "jina-test-key",
+      connectionId: "jina-connection",
+      connectionName: "Jina Test",
+      _connection: {
+        testStatus: "unavailable",
+        lastError: "old error",
+        modelLock___all: "2026-01-01T00:00:00.000Z",
+      },
+    });
+    mocks.checkAndRefreshToken.mockImplementation(async (_provider, credentials) => credentials);
+    mocks.handleFetchCore.mockResolvedValue({
+      success: true,
+      data: { provider: "jina-reader", content: { text: "ok" } },
+    });
+  });
+
+  it("clears a stale provider lock after a successful fetch", async () => {
+    const response = await handleFetch(new Request("http://localhost/v1/web/fetch", {
+      method: "POST",
+      headers: { "Content-Type": "application/json" },
+      body: JSON.stringify({
+        provider: "jina-reader",
+        url: "https://example.com/article",
+      }),
+    }));
+
+    expect(response.status).toBe(200);
+    expect(mocks.clearAccountError).toHaveBeenCalledWith(
+      "jina-connection",
+      expect.objectContaining({ connectionName: "Jina Test" }),
+    );
+    expect(mocks.markAccountUnavailable).not.toHaveBeenCalled();
+  });
+});