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/unit/web/tool-registry.test.ts

@@ -475,7 +475,7 @@ describe("CropSettingsWrapper", () => {
   it("renders null when cropProps is undefined", () => {
     const entry = getToolRegistryEntry("crop");
     expect(entry).toBeDefined();
-    const { container } = renderSettings(entry!.Settings as never);
+    const { container } = renderSettings(entry?.Settings as never);
     expect(container.innerHTML).toBe("");
   });
 
@@ -493,7 +493,7 @@ describe("CropSettingsWrapper", () => {
       onAspectChange: vi.fn(),
       onGridToggle: vi.fn(),
     };
-    const { container } = renderSettings(entry!.Settings as never, { cropProps });
+    const { container } = renderSettings(entry?.Settings as never, { cropProps });
     expect(container).toBeDefined();
   });
 });
@@ -502,7 +502,7 @@ describe("EraseObjectSettingsWrapper", () => {
   it("renders null when eraserProps is undefined", () => {
     const entry = getToolRegistryEntry("erase-object");
     expect(entry).toBeDefined();
-    const { container } = renderSettings(entry!.Settings as never);
+    const { container } = renderSettings(entry?.Settings as never);
     expect(container.innerHTML).toBe("");
   });
 
@@ -515,7 +515,7 @@ describe("EraseObjectSettingsWrapper", () => {
       brushSize: 20,
       onBrushSizeChange: vi.fn(),
     };
-    const { container } = renderSettings(entry!.Settings as never, { eraserProps });
+    const { container } = renderSettings(entry?.Settings as never, { eraserProps });
     expect(container).toBeDefined();
   });
 });
@@ -524,7 +524,7 @@ describe("makeColorSettingsComponent", () => {
   it("adjust-colors Settings renders without throwing", () => {
     const entry = getToolRegistryEntry("adjust-colors");
     expect(entry).toBeDefined();
-    const { container } = renderSettings(entry!.Settings as never, {
+    const { container } = renderSettings(entry?.Settings as never, {
       onPreviewFilter: vi.fn(),
     });
     expect(container).toBeDefined();