fix(discord): use GuildInteractionUser.Permissions instead of REST guild lookup

Replace REST GetGuildAsync/GetGuildUserAsync calls with authoritative
member.Permissions from the slash-command interaction payload. Discord
already resolves channel/guild permissions in the interaction JSON, so
we no longer need to fetch the guild via REST (which returns 404 when
the bot is not a REST member of the guild, e.g. user-installed apps).

Keep a best-effort GetGuildAsync call only to obtain OwnerId for the
permission checker fallback, swallowing 404 silently.

Bump version → 3.0.7

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

compose.yaml

@@ -49,7 +49,7 @@ services:
         crond -f
 
   bot:
-    image: git.codeanddice.ru/toutsu/gmrelay-bot:3.0.6
+    image: git.codeanddice.ru/toutsu/gmrelay-bot:3.0.7
     restart: always
     depends_on:
       db:
@@ -67,7 +67,7 @@ services:
       retries: 3
 
   discord:
-    image: git.codeanddice.ru/toutsu/gmrelay-discord-bot:3.0.6
+    image: git.codeanddice.ru/toutsu/gmrelay-discord-bot:3.0.7
     restart: always
     depends_on:
       db:
@@ -84,7 +84,7 @@ services:
       retries: 3
 
   web:
-    image: git.codeanddice.ru/toutsu/gmrelay-web:3.0.6
+    image: git.codeanddice.ru/toutsu/gmrelay-web:3.0.7
     restart: always
     depends_on:
       db: