test: massive test coverage expansion (+1,437 tests, 22 new files)

Expand test coverage across all layers via 14 parallel agents:

Unit tests (3,378 total, +534):
- First-ever AI sidecar tests (157 tests covering bridge lifecycle, all 12 tool modules)
- API route infrastructure (auth, pipeline, batch, settings, teams, roles, audit, api-keys, files, docs)
- Lib coverage improvements (audit 7%->95%, worker-pool 33%->100%)
- Web store/lib gap fills (features-store, tool-registry)

Integration tests (4,403 total, +903):
- Expanded 19 tool test files with parameter variations, format edge cases, boundary values
- Cross-format matrix: 290 tests covering 14 tools x 17 formats
- Adversarial/edge cases: 63 tests for extreme inputs, concurrent requests, corrupted files

E2E-Docker (125 new tests):
- Expanded 8 spec files + 1 new file covering all 49 tools
- Added HEIC/format handling, auth failures, download verification

GUI E2E (expanded 28 spec files):
- Navigation, responsive layout, keyboard shortcuts
- All 51 tool UIs with settings, processing, display modes
- Batch/pipeline workflows, settings/RBAC, visual regression
- Resilience, accessibility (ARIA, contrast, focus), performance budgets

tests/integration/watermark-text.test.ts

@@ -586,6 +586,183 @@ describe("watermark-text", () => {
     expect(json.downloadUrl).toBeDefined();
   });
 
+  // ── Zero opacity watermark ────────────────────────────────────────
+
+  it("applies watermark with zero opacity (invisible)", async () => {
+    const { body, contentType } = createMultipartPayload([
+      { name: "file", filename: "test.png", contentType: "image/png", content: PNG },
+      {
+        name: "settings",
+        content: JSON.stringify({ text: "Ghost", opacity: 0, fontSize: 24 }),
+      },
+    ]);
+
+    const res = await app.inject({
+      method: "POST",
+      url: "/api/v1/tools/watermark-text",
+      headers: { authorization: `Bearer ${adminToken}`, "content-type": contentType },
+      body,
+    });
+
+    expect(res.statusCode).toBe(200);
+    const json = JSON.parse(res.body);
+    expect(json.downloadUrl).toBeDefined();
+  });
+
+  // ── Minimum font size boundary ──────────────────────────────────
+
+  it("applies minimum font size (8)", async () => {
+    const { body, contentType } = createMultipartPayload([
+      { name: "file", filename: "test.png", contentType: "image/png", content: PNG },
+      {
+        name: "settings",
+        content: JSON.stringify({ text: "Tiny font", fontSize: 8, position: "top-left" }),
+      },
+    ]);
+
+    const res = await app.inject({
+      method: "POST",
+      url: "/api/v1/tools/watermark-text",
+      headers: { authorization: `Bearer ${adminToken}`, "content-type": contentType },
+      body,
+    });
+
+    expect(res.statusCode).toBe(200);
+  });
+
+  // ── Rejects fontSize below minimum ──────────────────────────────
+
+  it("rejects fontSize below minimum (<8)", async () => {
+    const { body, contentType } = createMultipartPayload([
+      { name: "file", filename: "test.png", contentType: "image/png", content: PNG },
+      {
+        name: "settings",
+        content: JSON.stringify({ text: "Bad", fontSize: 7 }),
+      },
+    ]);
+
+    const res = await app.inject({
+      method: "POST",
+      url: "/api/v1/tools/watermark-text",
+      headers: { authorization: `Bearer ${adminToken}`, "content-type": contentType },
+      body,
+    });
+
+    expect(res.statusCode).toBe(400);
+  });
+
+  // ── Rejects fontSize above maximum ──────────────────────────────
+
+  it("rejects fontSize above maximum (>1000)", async () => {
+    const { body, contentType } = createMultipartPayload([
+      { name: "file", filename: "test.png", contentType: "image/png", content: PNG },
+      {
+        name: "settings",
+        content: JSON.stringify({ text: "Bad", fontSize: 1001 }),
+      },
+    ]);
+
+    const res = await app.inject({
+      method: "POST",
+      url: "/api/v1/tools/watermark-text",
+      headers: { authorization: `Bearer ${adminToken}`, "content-type": contentType },
+      body,
+    });
+
+    expect(res.statusCode).toBe(400);
+  });
+
+  // ── TIFF input format ───────────────────────────────────────────
+
+  it("processes TIFF input format", async () => {
+    const TIFF = readFileSync(join(FIXTURES, "formats", "sample.tiff"));
+    const { body, contentType } = createMultipartPayload([
+      { name: "file", filename: "test.tiff", contentType: "image/tiff", content: TIFF },
+      { name: "settings", content: JSON.stringify({ text: "TIFF Test" }) },
+    ]);
+
+    const res = await app.inject({
+      method: "POST",
+      url: "/api/v1/tools/watermark-text",
+      headers: { authorization: `Bearer ${adminToken}`, "content-type": contentType },
+      body,
+    });
+
+    expect(res.statusCode).toBe(200);
+    const json = JSON.parse(res.body);
+    expect(json.downloadUrl).toBeDefined();
+  });
+
+  // ── Multiline text (newlines in text) ───────────────────────────
+
+  it("handles text with newline characters", async () => {
+    const { body, contentType } = createMultipartPayload([
+      { name: "file", filename: "test.png", contentType: "image/png", content: PNG },
+      {
+        name: "settings",
+        content: JSON.stringify({ text: "Line1\nLine2" }),
+      },
+    ]);
+
+    const res = await app.inject({
+      method: "POST",
+      url: "/api/v1/tools/watermark-text",
+      headers: { authorization: `Bearer ${adminToken}`, "content-type": contentType },
+      body,
+    });
+
+    expect(res.statusCode).toBe(200);
+    const json = JSON.parse(res.body);
+    expect(json.downloadUrl).toBeDefined();
+  });
+
+  // ── Tiled with max fontSize on small image ──────────────────────
+
+  it("handles tiled watermark with large fontSize on small image", async () => {
+    const { body, contentType } = createMultipartPayload([
+      { name: "file", filename: "test.png", contentType: "image/png", content: PNG },
+      {
+        name: "settings",
+        content: JSON.stringify({
+          text: "BIG",
+          position: "tiled",
+          fontSize: 200,
+          rotation: 45,
+        }),
+      },
+    ]);
+
+    const res = await app.inject({
+      method: "POST",
+      url: "/api/v1/tools/watermark-text",
+      headers: { authorization: `Bearer ${adminToken}`, "content-type": contentType },
+      body,
+    });
+
+    expect(res.statusCode).toBe(200);
+  });
+
+  // ── Color with 8-char hex (should be rejected) ──────────────────
+
+  it("rejects 8-character hex color (no alpha support)", async () => {
+    const { body, contentType } = createMultipartPayload([
+      { name: "file", filename: "test.png", contentType: "image/png", content: PNG },
+      {
+        name: "settings",
+        content: JSON.stringify({ text: "Bad", color: "#FF000080" }),
+      },
+    ]);
+
+    const res = await app.inject({
+      method: "POST",
+      url: "/api/v1/tools/watermark-text",
+      headers: { authorization: `Bearer ${adminToken}`, "content-type": contentType },
+      body,
+    });
+
+    expect(res.statusCode).toBe(400);
+  });
+
   // ── Preserves image dimensions ───────────────────────────────────
 
   it("preserves image dimensions after watermark", async () => {