test(e2e): modernize stale routes for 2.0 section URLs (#347)

The e2e specs predate the 2.0 section-route migration and navigated to
single-segment tool URLs (/resize) that now 404 (App.tsx only mounts
/:section/:toolId). This broke the whole e2e suite (Cross-Browser, Device
Matrix, E2E Full, Visual) - part of the known stale-spec backlog.

- Sweep 929 goto("/<tool>") -> goto("/<section>/<tool>") across 45 spec
  files, using the authoritative TOOLS + toolSection() mapping. Two-segment
  routes, top-level routes (/automate, /editor, ...), and intentional 404
  tests (/nonexistent-*) are untouched.
- Implement the legacy redirects the specs already assert: the 1.x color
  tools (brightness-contrast, saturation, color-channels, color-effects)
  redirect to /image/adjust-colors (App.tsx). Good for old bookmarks too.
- Remove the analytics-consent page tests (gui-navigation + gui-visual);
  #336 deleted that page.

Mechanical + biome-clean + web typecheck passes. Browser-specific behavior
can only be confirmed by the nightly e2e jobs.

tests/e2e/gui-qa-fixes.spec.ts

@@ -14,7 +14,7 @@ test.describe("QA Fixes Verification", () => {
   });
 
   test("tool page loads correctly", async ({ page }) => {
-    await page.goto("/resize");
+    await page.goto("/image/resize");
     await page.waitForLoadState("networkidle");
     // Should see resize tool content
     await expect(page.locator("text=Resize").first()).toBeVisible({ timeout: 10_000 });
@@ -98,7 +98,7 @@ test.describe("QA Fixes Verification", () => {
   });
 
   test("dropzone uses i18n strings (no hardcoded 'or')", async ({ page }) => {
-    await page.goto("/resize");
+    await page.goto("/image/resize");
     await page.waitForLoadState("networkidle");
     // The dropzone should be visible with upload button
     const uploadBtn = page.locator("text=Upload").first();