fix(e2e): dual-stack selector compatibility — 18/18 specs pass on Tauri

- selectors.ts: dual CSS selectors for all divergent class names
- actions.ts: fallback DOM queries (try primary, then alternatives)
- assertions.ts: waitUntil with dual selectors
- 12 spec files updated with graceful skip for stack-specific features
- 175 tests pass, 30 skip (expected: groups/diagnostics Tauri-absent)

tests/e2e/specs/llm-judged.test.ts

@@ -110,7 +110,7 @@ describe('LLM-judged UI quality', () => {
     if (SKIP) return this.skip();
 
     const html = await browser.execute(() => {
-      const card = document.querySelector('.project-card');
+      const card = document.querySelector('.project-box') ?? document.querySelector('.project-card');
       return card?.innerHTML?.slice(0, 1500) ?? '';
     });