fix: tolerate season-reset payloads in /sq-info and stop duplicate error embeds

obtain_clan_new_points treated a missing `astat` or `member_ratings` block as
"squadron unavailable or deleted". After a season reset the game API omits those
blocks for inactive/unranked squadrons even though the clan and its roster still
exist, so /sq-info wrongly reported real squadrons (e.g. DSPL, 513th) as
nonexistent. Require a `members` roster to consider the payload valid (genuinely
deleted clans return CLAN_IS_NOT_EXISTS JSON handled upstream) and default both
stat blocks to zero, so the squadron renders at 0 points instead of erroring.

permission_fail was invoked twice per error because discord.py dispatches to
both the command-local `@cmd.error` handler and the global `@tree.error`
handler. Combined with a public defer, this produced a duplicated error message
(one public, one ephemeral). Guard on interaction.extras so the embed is sent
at most once per interaction.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

BOT/utils.py

@@ -598,6 +598,15 @@ def gate_entitle(required_tier: str):
 
 async def permission_fail(interaction: discord.Interaction, error):
     """Handle permission-related errors with appropriate embeds."""
+    # discord.py dispatches a command error to BOTH the command's local
+    # `@cmd.error` handler and the global `@tree.error` handler (see
+    # app_commands/tree.py). Since both route here, guard against sending the
+    # error embed twice for the same interaction — the second send would land
+    # as a separate (and, after a public defer, differently-scoped) message.
+    if interaction.extras.get("_permission_fail_handled"):
+        return
+    interaction.extras["_permission_fail_handled"] = True
+
     lang = await guild_lang(interaction.guild_id) if interaction.guild_id else "en"
     if isinstance(error, BlacklistCheckFailure):
         reason = getattr(error, "reason", None)