test: expand test coverage across unit, integration, e2e, and e2e-docker suites

Add ~210 new tests filling gaps identified by a comprehensive 14-agent
coverage audit. Unit+integration tests go from 9,388 to 9,484 (all passing).

Unit tests (+36):
- AI bridge: OOM fallback path, custom tier option
- Web lib: api-errors, format date/datetime, tool-i18n coverage

Integration tests (+19):
- Format matrix: ai-canvas-expand and find-duplicates added to cross-format matrix
- Adversarial: SVG XXE attacks, SQL injection in settings, request body size
  limits, race conditions with identical filenames

E2E Docker (+3):
- ai-canvas-expand tool coverage with HEIC input and edge cases

E2E GUI (~150+):
- Navigation: login rate limiting, ai-canvas-expand in parameterized list
- Responsive: dropzone visibility, text readability, dialog bounds at all viewports
- Keyboard: shortcuts verified from automate, files, tool, and fullscreen pages
- Tool UI: undo/state-reset for 16 tools, crop canvas drag handles, rotate/border
  live preview, linked aspect-ratio inputs for resize
- Batch: per-image undo isolation, batch compress/convert/rotate (not just resize)
- Pipeline: tool palette search, step collapse/expand visibility
- Settings: audit log entry verification, system settings persistence, teams CRUD,
  role permission toggling
- RBAC: user/editor 403 on roles/teams endpoints, privilege escalation prevention,
  cross-role tab parity documented as intentional
- Accessibility: skip-to-content link (WCAG 2.4.1), comprehensive color contrast
  for all headings/body/buttons in both themes with DOM-walking background detection
- Resilience: auth expiry 401 redirect, rate limit 429 handling
- Performance: JS heap memory stability for tool navigation, dialog cycling,
  upload/clear cycles, rapid page navigation

tests/unit/web/tool-i18n.test.ts

@@ -0,0 +1,81 @@
+import { describe, expect, it } from "vitest";
+import { getCategoryName, getToolDescription, getToolName } from "@/lib/tool-i18n";
+
+// Minimal mock shaped like TranslationKeys with tools and categories
+function makeT(
+  tools: Record<string, { name?: string; description?: string }>,
+  categories: Record<string, string>,
+) {
+  return { tools, categories } as Parameters<typeof getToolName>[0];
+}
+
+describe("getToolName", () => {
+  const t = makeT(
+    {
+      resize: { name: "Resize Image", description: "Change dimensions" },
+      compress: { name: "Compress" },
+      "no-name": { description: "Only has description" },
+    },
+    {},
+  );
+
+  it("returns translated name when available", () => {
+    expect(getToolName(t, "resize", "Fallback")).toBe("Resize Image");
+  });
+
+  it("returns fallback when tool entry has no name", () => {
+    expect(getToolName(t, "no-name", "Fallback Name")).toBe("Fallback Name");
+  });
+
+  it("returns fallback when tool id is not in translations", () => {
+    expect(getToolName(t, "nonexistent", "Default Name")).toBe("Default Name");
+  });
+
+  it("returns fallback for empty tool id", () => {
+    expect(getToolName(t, "", "Empty Fallback")).toBe("Empty Fallback");
+  });
+});
+
+describe("getToolDescription", () => {
+  const t = makeT(
+    {
+      resize: { name: "Resize", description: "Change image dimensions" },
+      "no-desc": { name: "Tool Without Desc" },
+    },
+    {},
+  );
+
+  it("returns translated description when available", () => {
+    expect(getToolDescription(t, "resize", "Fallback")).toBe("Change image dimensions");
+  });
+
+  it("returns fallback when tool entry has no description", () => {
+    expect(getToolDescription(t, "no-desc", "Default Desc")).toBe("Default Desc");
+  });
+
+  it("returns fallback when tool id is not in translations", () => {
+    expect(getToolDescription(t, "unknown", "Fallback Desc")).toBe("Fallback Desc");
+  });
+});
+
+describe("getCategoryName", () => {
+  const t = makeT(
+    {},
+    {
+      transform: "Transform",
+      effects: "Effects & Filters",
+    },
+  );
+
+  it("returns translated category name when available", () => {
+    expect(getCategoryName(t, "transform", "Fallback")).toBe("Transform");
+  });
+
+  it("returns fallback when category id is not in translations", () => {
+    expect(getCategoryName(t, "unknown-cat", "Unknown Category")).toBe("Unknown Category");
+  });
+
+  it("returns fallback for empty category id", () => {
+    expect(getCategoryName(t, "", "Empty")).toBe("Empty");
+  });
+});