feat(qa): add smoke test suite + post-deploy workflow

- e2e/api/smoke.spec.ts — 9 @smoke API tests covering health, auth roundtrip,
  token refresh, listings, search, payments, subscriptions, and inquiries
- e2e/web/smoke.spec.ts — 7 @smoke Web tests covering homepage, login/register
  pages, listings, search, listing detail 404 handling, and console-error check
- playwright.config.ts — smoke-api and smoke-web projects (grep: /@smoke/)
  allowing targeted post-deploy execution without the full suite
- .github/workflows/smoke.yml — workflow_dispatch + workflow_call trigger for
  running only the @smoke subset against staging or production URLs

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

playwright.config.ts

@@ -58,6 +58,24 @@ export default defineConfig({
         baseURL: process.env.WEB_BASE_URL ?? `http://localhost:${WEB_PORT}`,
       },
     },
+    // Smoke projects — subsets of api/web tagged @smoke for post-deploy checks
+    {
+      name: 'smoke-api',
+      testDir: './e2e/api',
+      grep: /@smoke/,
+      use: {
+        baseURL: process.env.API_BASE_URL ?? `http://localhost:${API_PORT}/api/v1/`,
+      },
+    },
+    {
+      name: 'smoke-web',
+      testDir: './e2e/web',
+      grep: /@smoke/,
+      use: {
+        ...devices['Desktop Chrome'],
+        baseURL: process.env.WEB_BASE_URL ?? `http://localhost:${WEB_PORT}`,
+      },
+    },
   ],
 
   webServer: [