refactor(ci): use marker comments instead of regex for tracker workflow

Add TRACKER: HTML comment markers to COMPATIBILITY.md, README.md, and
all 5 translation READMEs. Rewrite gitea-tracker.yml to use grep -n
for precise line-based insertion and sed line-address editing.

Markers introduced:
- TRACKER:QUICK-REF-MAX  — Quick Reference max tested version
- TRACKER:VERSION-INSERT — Version History row insertion point
- TRACKER:LATEST-VERIFIED — latest verified note version
- TRACKER:BADGE — shields.io badge version
- TRACKER:LATEST-TESTED — latest tested version in READMEs

Co-Authored-By: Claude <noreply@anthropic.com>

docs/README.ru.md

@@ -58,7 +58,7 @@ cd tools && go run . dev
 ## Совместимость
 
 - **Gitea 1.25+** — структура директорий из v1.25
-- **Последняя проверка:** Gitea 1.26.4
+- **Последняя проверка:** Gitea 1.26.4<!-- TRACKER:LATEST-TESTED -->
 - 100% совместимость с официальными шаблонами Gitea — см. [COMPATIBILITY.md](COMPATIBILITY.md)
 
 ## Лицензия