test: expand API and GUI test coverage across all tools

Add ~500 new E2E tests and ~300 new integration tests covering:

- 24 new GUI E2E specs: navigation, responsive layout, keyboard shortcuts,
  tool UI for all 35 non-AI tools, batch/pipeline workflows, settings/RBAC,
  visual regression, accessibility, and performance budgets
- 3 new E2E-Docker specs: batch workflows, advanced pipelines, cross-format
- 1 new adversarial integration test: memory pressure, corrupted files,
  unicode filenames, extreme dimensions, pipeline/batch edge cases
- 29 expanded integration test files: HEIC/HEIF input, large files, parameter
  boundaries, batch processing, format edge cases across all tools
- Cross-format matrix expanded: 641 tests covering every tool x 18 formats
- AI bridge unit tests expanded: lifecycle, tool modules, error propagation
- Unit test gaps filled: analytics, tool-registry, web stores

Also fixes:
- vitest.config.ts: exclude e2e-docs and e2e-landing from Vitest runner
- AI E2E specs: add sidecar health check to skip gracefully when Python
  AI backend is not running instead of timing out

tests/integration/image-to-pdf.test.ts

@@ -589,4 +589,174 @@ describe("image-to-pdf", () => {
     const json = JSON.parse(res.body);
     expect(json.compression.targetRequested).toBe(500 * 1024);
   });
+
+  // ── Large stress file ────────────────────────────────────────────
+
+  it("converts stress-large.jpg to PDF", async () => {
+    const LARGE = readFileSync(join(FIXTURES, "content", "stress-large.jpg"));
+    const { body, contentType } = createMultipartPayload([
+      { name: "file", filename: "large.jpg", contentType: "image/jpeg", content: LARGE },
+      { name: "settings", content: JSON.stringify({}) },
+    ]);
+
+    const res = await app.inject({
+      method: "POST",
+      url: "/api/v1/tools/image-to-pdf",
+      headers: { authorization: `Bearer ${adminToken}`, "content-type": contentType },
+      body,
+    });
+
+    expect(res.statusCode).toBe(200);
+    const json = JSON.parse(res.body);
+    expect(json.pages).toBe(1);
+    expect(json.processedSize).toBeGreaterThan(0);
+  });
+
+  // ── 5+ images batch PDF ──────────────────────────────────────────
+
+  it("creates 5-page PDF from five images", async () => {
+    const WEBP = readFileSync(join(FIXTURES, "test-50x50.webp"));
+    const TINY = readFileSync(join(FIXTURES, "test-1x1.png"));
+    const { body, contentType } = createMultipartPayload([
+      { name: "file", filename: "p1.png", contentType: "image/png", content: PNG },
+      { name: "file", filename: "p2.jpg", contentType: "image/jpeg", content: JPG },
+      { name: "file", filename: "p3.webp", contentType: "image/webp", content: WEBP },
+      { name: "file", filename: "p4.png", contentType: "image/png", content: TINY },
+      { name: "file", filename: "p5.png", contentType: "image/png", content: PNG },
+      { name: "settings", content: JSON.stringify({}) },
+    ]);
+
+    const res = await app.inject({
+      method: "POST",
+      url: "/api/v1/tools/image-to-pdf",
+      headers: { authorization: `Bearer ${adminToken}`, "content-type": contentType },
+      body,
+    });
+
+    expect(res.statusCode).toBe(200);
+    const json = JSON.parse(res.body);
+    expect(json.pages).toBe(5);
+    expect(json.processedSize).toBeGreaterThan(0);
+  });
+
+  // ── A5 portrait with zero margin ─────────────────────────────────
+
+  it("handles A5 portrait with zero margin", async () => {
+    const { body, contentType } = createMultipartPayload([
+      { name: "file", filename: "test.png", contentType: "image/png", content: PNG },
+      {
+        name: "settings",
+        content: JSON.stringify({
+          pageSize: "A5",
+          orientation: "portrait",
+          margin: 0,
+        }),
+      },
+    ]);
+
+    const res = await app.inject({
+      method: "POST",
+      url: "/api/v1/tools/image-to-pdf",
+      headers: { authorization: `Bearer ${adminToken}`, "content-type": contentType },
+      body,
+    });
+
+    expect(res.statusCode).toBe(200);
+    const json = JSON.parse(res.body);
+    expect(json.pages).toBe(1);
+  });
+
+  // ── Rejects unauthenticated request ──────────────────────────────
+
+  it("rejects unauthenticated request", async () => {
+    const { body, contentType } = createMultipartPayload([
+      { name: "file", filename: "test.png", contentType: "image/png", content: PNG },
+      { name: "settings", content: JSON.stringify({}) },
+    ]);
+
+    const res = await app.inject({
+      method: "POST",
+      url: "/api/v1/tools/image-to-pdf",
+      headers: { "content-type": contentType },
+      body,
+    });
+
+    expect(res.statusCode).toBe(401);
+  });
+
+  // ── Multi-image with target size ─────────────────────────────────
+
+  it("compresses 3-image PDF with target size", async () => {
+    const WEBP = readFileSync(join(FIXTURES, "test-50x50.webp"));
+    const { body, contentType } = createMultipartPayload([
+      { name: "file", filename: "p1.png", contentType: "image/png", content: PNG },
+      { name: "file", filename: "p2.jpg", contentType: "image/jpeg", content: JPG },
+      { name: "file", filename: "p3.webp", contentType: "image/webp", content: WEBP },
+      {
+        name: "settings",
+        content: JSON.stringify({ targetSize: { value: 2, unit: "MB" } }),
+      },
+    ]);
+
+    const res = await app.inject({
+      method: "POST",
+      url: "/api/v1/tools/image-to-pdf",
+      headers: { authorization: `Bearer ${adminToken}`, "content-type": contentType },
+      body,
+    });
+
+    expect(res.statusCode).toBe(200);
+    const json = JSON.parse(res.body);
+    expect(json.pages).toBe(3);
+    expect(json.compression).toBeDefined();
+    expect(json.compression.targetMet).toBe(true);
+  });
+
+  // ── Letter landscape ─────────────────────────────────────────────
+
+  it("handles Letter landscape", async () => {
+    const { body, contentType } = createMultipartPayload([
+      { name: "file", filename: "test.png", contentType: "image/png", content: PNG },
+      {
+        name: "settings",
+        content: JSON.stringify({
+          pageSize: "Letter",
+          orientation: "landscape",
+          margin: 30,
+        }),
+      },
+    ]);
+
+    const res = await app.inject({
+      method: "POST",
+      url: "/api/v1/tools/image-to-pdf",
+      headers: { authorization: `Bearer ${adminToken}`, "content-type": contentType },
+      body,
+    });
+
+    expect(res.statusCode).toBe(200);
+    const json = JSON.parse(res.body);
+    expect(json.pages).toBe(1);
+  });
+
+  // ── Rejects invalid orientation ──────────────────────────────────
+
+  it("rejects invalid orientation value", async () => {
+    const { body, contentType } = createMultipartPayload([
+      { name: "file", filename: "test.png", contentType: "image/png", content: PNG },
+      {
+        name: "settings",
+        content: JSON.stringify({ orientation: "sideways" }),
+      },
+    ]);
+
+    const res = await app.inject({
+      method: "POST",
+      url: "/api/v1/tools/image-to-pdf",
+      headers: { authorization: `Bearer ${adminToken}`, "content-type": contentType },
+      body,
+    });
+
+    expect(res.statusCode).toBe(400);
+  });
 });