feat(a11y): add axe-core Playwright scorecard for 10 key routes

- Installs @axe-core/playwright at workspace root
- Creates e2e/a11y/scorecard.spec.ts scanning /, /search, /listings/[id],
  /listings/create, /login, /register, /dashboard, /agent/[id],
  /inquiries, /admin/moderation
- API mock layer lets pages render with stubbed JSON so axe sees real DOM
- Critical/serious violations fail the build; moderate/minor are recorded only
- Writes per-route JSON reports to e2e/a11y/reports/ (committed for before/after diffing in PRs)
- Adds dedicated "a11y" Playwright project in playwright.config.ts
- Pre-existing API unit test failures are unrelated to this change

Co-Authored-By: Paperclip <noreply@paperclip.ing>

playwright.config.ts

@@ -76,6 +76,15 @@ export default defineConfig({
         baseURL: process.env.WEB_BASE_URL ?? `http://localhost:${WEB_PORT}`,
       },
     },
+    // Accessibility scorecard — axe-core audit of 10 key routes
+    {
+      name: 'a11y',
+      testDir: './e2e/a11y',
+      use: {
+        ...devices['Desktop Chrome'],
+        baseURL: process.env.WEB_BASE_URL ?? `http://localhost:${WEB_PORT}`,
+      },
+    },
   ],
 
   webServer: [