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/e2e-docker/creative-tools.spec.ts

@@ -61,7 +61,7 @@ function buildMultipart(
   };
 }
 
-async function uploadFiles(page: Page, filePaths: string[]): Promise<void> {
+async function _uploadFiles(page: Page, filePaths: string[]): Promise<void> {
   const fileChooserPromise = page.waitForEvent("filechooser");
   const dropzone = page.locator("[class*='border-dashed']").first();
   await dropzone.click();
@@ -70,7 +70,7 @@ async function uploadFiles(page: Page, filePaths: string[]): Promise<void> {
   await page.waitForTimeout(3000);
 }
 
-async function waitForProcessingDone(page: Page, timeoutMs = 120_000): Promise<void> {
+async function _waitForProcessingDone(page: Page, timeoutMs = 120_000): Promise<void> {
   try {
     const spinner = page.locator("[class*='animate-spin']");
     if (await spinner.isVisible({ timeout: 3000 })) {