test: major coverage expansion — 18 new test files, ~830 new tests

Unit tests: 1354 → 1781 (+427)
- 11 new AI bridge module tests (packages/ai/ from 2/13 → 13/13 files)
- files-page-store (0% → full), pdf-to-image-store, features-store expanded
- saturation and edit-metadata image-engine operations
- analytics route, features route, web analytics lib, api-extended

Integration tests: ~2070 → 2320 (+250)
- 31 integration files expanded with branch-coverage-targeted tests
- progress.ts SSE endpoints (28% → comprehensive, +18 tests)
- gif-tools all modes (+18), pdf-to-image format variants (+13)
- Cross-format matrix expanded to 17 tools × 17 formats (467 tests)
- Adversarial: concurrent, memory pressure, unicode filenames, pipeline limits

E2E-Docker: +1020 lines across 6 spec files
- Info, colors, sharpening, base64, QR read, JXL/ICO/SVG formats
- Strip-metadata, image-enhancement, content-aware-resize expanded
- Batch pipelines, multi-format batches, HEIC input coverage

tests/integration/image-to-base64.test.ts

@@ -465,4 +465,175 @@ describe("image-to-base64", () => {
     expect(json.results[0].width).toBeLessThanOrEqual(50);
     expect(json.results[0].height).toBeLessThanOrEqual(50);
   });
+
+  // ── Branch coverage: line 83 (ignored invalid settings JSON) ──────
+
+  it("ignores invalid settings JSON (uses defaults)", async () => {
+    const { body, contentType } = createMultipartPayload([
+      { name: "file", filename: "test.png", contentType: "image/png", content: PNG },
+      { name: "settings", content: "not-json-at-all" },
+    ]);
+
+    const res = await app.inject({
+      method: "POST",
+      url: "/api/v1/tools/image-to-base64",
+      headers: { authorization: `Bearer ${adminToken}`, "content-type": contentType },
+      body,
+    });
+
+    // The route silently ignores invalid JSON and uses defaults
+    expect(res.statusCode).toBe(200);
+    const json = JSON.parse(res.body);
+    expect(json.results).toHaveLength(1);
+    expect(json.results[0].mimeType).toContain("image/");
+  });
+
+  // ── Branch coverage: lines 149-150 (default case in outputFormat switch) ──
+
+  it("handles unknown outputFormat falling through to default", async () => {
+    // Testing the "original" path with a non-HEIC, non-SVG format and no resize
+    const { body, contentType } = createMultipartPayload([
+      { name: "file", filename: "test.jpg", contentType: "image/jpeg", content: JPG },
+      { name: "settings", content: JSON.stringify({ outputFormat: "original" }) },
+    ]);
+
+    const res = await app.inject({
+      method: "POST",
+      url: "/api/v1/tools/image-to-base64",
+      headers: { authorization: `Bearer ${adminToken}`, "content-type": contentType },
+      body,
+    });
+
+    expect(res.statusCode).toBe(200);
+    const json = JSON.parse(res.body);
+    expect(json.results[0].mimeType).toBe("image/jpeg");
+  });
+
+  // ── Branch coverage: line 180 (overheadPercent = 0 for empty) ─────
+
+  it("handles 1x1 tiny image", async () => {
+    const TINY = readFileSync(join(FIXTURES, "test-1x1.png"));
+    const { body, contentType } = createMultipartPayload([
+      { name: "file", filename: "tiny.png", contentType: "image/png", content: TINY },
+      { name: "settings", content: JSON.stringify({}) },
+    ]);
+
+    const res = await app.inject({
+      method: "POST",
+      url: "/api/v1/tools/image-to-base64",
+      headers: { authorization: `Bearer ${adminToken}`, "content-type": contentType },
+      body,
+    });
+
+    expect(res.statusCode).toBe(200);
+    const json = JSON.parse(res.body);
+    expect(json.results[0].width).toBe(1);
+    expect(json.results[0].height).toBe(1);
+    expect(typeof json.results[0].overheadPercent).toBe("number");
+  });
+
+  // ── HEIC with resize ──────────────────────────────────────────────
+
+  it("converts HEIC to JPEG with resize applied", async () => {
+    const HEIC = readFileSync(join(FIXTURES, "test-200x150.heic"));
+    const { body, contentType } = createMultipartPayload([
+      { name: "file", filename: "photo.heic", contentType: "image/heic", content: HEIC },
+      { name: "settings", content: JSON.stringify({ maxWidth: 50 }) },
+    ]);
+
+    const res = await app.inject({
+      method: "POST",
+      url: "/api/v1/tools/image-to-base64",
+      headers: { authorization: `Bearer ${adminToken}`, "content-type": contentType },
+      body,
+    });
+
+    expect(res.statusCode).toBe(200);
+    const json = JSON.parse(res.body);
+    expect(json.results[0].mimeType).toBe("image/jpeg");
+    expect(json.results[0].width).toBeLessThanOrEqual(50);
+  });
+
+  // ── HEIC with explicit format conversion ──────────────────────────
+
+  it("converts HEIC to PNG when outputFormat is png", async () => {
+    const HEIC = readFileSync(join(FIXTURES, "test-200x150.heic"));
+    const { body, contentType } = createMultipartPayload([
+      { name: "file", filename: "photo.heic", contentType: "image/heic", content: HEIC },
+      { name: "settings", content: JSON.stringify({ outputFormat: "png" }) },
+    ]);
+
+    const res = await app.inject({
+      method: "POST",
+      url: "/api/v1/tools/image-to-base64",
+      headers: { authorization: `Bearer ${adminToken}`, "content-type": contentType },
+      body,
+    });
+
+    expect(res.statusCode).toBe(200);
+    const json = JSON.parse(res.body);
+    expect(json.results[0].mimeType).toBe("image/png");
+  });
+
+  // ── Original format with resize (no format conversion) ────────────
+
+  it("preserves original format when only resize is requested", async () => {
+    const { body, contentType } = createMultipartPayload([
+      { name: "file", filename: "test.png", contentType: "image/png", content: PNG },
+      { name: "settings", content: JSON.stringify({ maxWidth: 100 }) },
+    ]);
+
+    const res = await app.inject({
+      method: "POST",
+      url: "/api/v1/tools/image-to-base64",
+      headers: { authorization: `Bearer ${adminToken}`, "content-type": contentType },
+      body,
+    });
+
+    expect(res.statusCode).toBe(200);
+    const json = JSON.parse(res.body);
+    expect(json.results[0].mimeType).toContain("image/");
+    expect(json.results[0].width).toBeLessThanOrEqual(100);
+  });
+
+  // ── Large stress file ─────────────────────────────────────────────
+
+  it("converts stress-large.jpg to base64", 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({ maxWidth: 200 }) },
+    ]);
+
+    const res = await app.inject({
+      method: "POST",
+      url: "/api/v1/tools/image-to-base64",
+      headers: { authorization: `Bearer ${adminToken}`, "content-type": contentType },
+      body,
+    });
+
+    expect(res.statusCode).toBe(200);
+    const json = JSON.parse(res.body);
+    expect(json.results[0].base64.length).toBeGreaterThan(0);
+    expect(json.results[0].width).toBeLessThanOrEqual(200);
+  });
+
+  // ── No settings at all ────────────────────────────────────────────
+
+  it("works when no settings field is provided at all", async () => {
+    const { body, contentType } = createMultipartPayload([
+      { name: "file", filename: "test.png", contentType: "image/png", content: PNG },
+    ]);
+
+    const res = await app.inject({
+      method: "POST",
+      url: "/api/v1/tools/image-to-base64",
+      headers: { authorization: `Bearer ${adminToken}`, "content-type": contentType },
+      body,
+    });
+
+    expect(res.statusCode).toBe(200);
+    const json = JSON.parse(res.body);
+    expect(json.results).toHaveLength(1);
+  });
 });