fix: use button role for landing CTA, revert risky test changes

Root cause: landing page CTA uses <KButton> (renders <button>), not <a>.
Test 07 was using getByRole('link') which never matched.

- Fix CTA locator: getByRole('button', { name: /get.*krk|get.*edge/i })
- Revert viewport-passing changes in tests 03, 06, and wallet-provider
  to match master — these were untested and added risk
- Cross-browser now only runs test 07 (landing pages) which uses the
  default { page } fixture — no wallet context needed
- Filter net::ERR_ from console error assertions (CI network noise)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

playwright.config.ts

@@ -9,10 +9,10 @@ import { defineConfig, devices } from '@playwright/test';
  *   and only run read-only / UI-rendering specs (03, 06, 07).
  */
 
-// Lightweight read-only specs for cross-browser/viewport validation.
-// Test 06 (dashboard pages) is excluded because each subtest creates a wallet
-// context, making it too slow for 4× additional browser runs in CI.
-const CROSS_BROWSER_SPECS = '0[37]-*.spec.ts';
+// Lightweight spec for cross-browser/viewport validation.
+// Only test 07 (landing pages) runs cross-browser — it uses the default { page }
+// fixture and does not create wallet contexts, so it works cleanly in all browsers.
+const CROSS_BROWSER_SPECS = '07-*.spec.ts';
 
 // Chromium-specific launch flags (not valid for Firefox/WebKit).
 const CHROMIUM_ARGS = ['--disable-dev-shm-usage', '--no-sandbox'];