fix(mentionhelp): default to English on locale lookup failure, use Polish only for pl locales

mentionhelp.py

@@ -1,17 +1,30 @@
 import discord
 from redbot.core import commands
+from redbot.core.i18n import get_locale_from_guild
 
 
 class MentionHelp(commands.Cog):
     def __init__(self, bot):
         self.bot = bot
 
-    def build_help_embed(self, message, prefix_text, main_prefix):
+    @staticmethod
+    def _is_polish_locale(locale: str) -> bool:
+        if not isinstance(locale, str):
+            return False
+        return locale.lower().startswith("pl")
+
+    def build_help_embed(self, message, main_prefix, locale):
+        is_polish = self._is_polish_locale(locale)
+        title = "Pomoc" if is_polish else "Help"
+        description = (
+            f"Użyj `{main_prefix}help`, aby zobaczyć wszystkie komendy bota."
+            if is_polish
+            else f"Use `{main_prefix}help` to see all bot commands."
+        )
+
         embed = discord.Embed(
-            title="Pomoc",
-            description=(
-                f"Użyj `{main_prefix}help`, aby zobaczyć wszystkie komendy bota."
-            ),
+            title=title,
+            description=description,
             color=0xEB459E
         )
 
@@ -58,7 +71,12 @@ class MentionHelp(commands.Cog):
 
             visible_prefixes = [p for p in prefixes if not p.startswith("<@")]
             main_prefix = visible_prefixes[0] if visible_prefixes else prefixes[0]
-            prefix_text = ", ".join(visible_prefixes) if visible_prefixes else ", ".join(prefixes)
+            try:
+                locale = await get_locale_from_guild(self.bot, message.guild)
+            except Exception:
+                locale = "en-US"
+            if not isinstance(locale, str) or not locale.strip():
+                locale = "en-US"
 
-            embed = self.build_help_embed(message, prefix_text, main_prefix)
+            embed = self.build_help_embed(message, main_prefix, locale)
             await message.channel.send(embed=embed)