GRM-86: feat: add Polish as officially supported language

src/gitea_runner_manager/i18n.py

@@ -1,7 +1,7 @@
 """Simple i18n for GRM console messages.
 
 Set GRM_LANG environment variable to override the default English.
-Supported: en, bg, de, ru, zh.
+Supported: en, bg, de, ru, zh, pl.
 """
 
 from __future__ import annotations
@@ -22,7 +22,7 @@ def _(key: str, **kwargs: object) -> str:
     If unset, English is always returned regardless of system locale.
     """
     lang = os.getenv("GRM_LANG", "en")
-    if lang not in ("en", "bg", "de", "ru", "zh"):
+    if lang not in ("en", "bg", "de", "ru", "zh", "pl"):
         lang = "en"
     template = TRANSLATIONS.get(key, {}).get(lang, key)
     return template.format(**kwargs)