i18n slice 1 (A.2-A.4, A.6): narrowed English mask, marker coverage test, English retrieval stems, parse timing

Five v0.247.0 fixtures re-captured from UNCONVERTED v0.246.0 (89dd3e94) because their
one-word Hungarian data values had to become multi-word; two new cases (backups_tier_due,
app_info_installable) captured the same way — the coverage test found both gaps.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0159rPz1ZhFKsS53msqPYxtS

controller/internal/web/testdata/i18n_parity/app_info_available.html

@@ -189,7 +189,7 @@
         
         <div class="stack-meta-badges">
             <span class="meta-badge">~64M RAM</span>
-            <span class="meta-badge">Eszközök</span>
+            <span class="meta-badge">Hasznos eszközök</span>
             
             <span class="meta-badge meta-badge-ok">Pi kompatibilis</span>