fix(guild): implement alliance application toggle (#166)

Alliance applications were hardcoded to always-open. Add a `recruiting`
column to guild_alliances and handle OperateJoint actions 0x06 (Allow)
and 0x07 (Deny) confirmed via Wii U debug symbols. Only the parent
guild leader can toggle the setting, matching the existing disband guard.

server/channelserver/repo_guild_alliance.go

@@ -11,6 +11,7 @@ SELECT
 ga.id,
 ga.name,
 created_at,
+ga.recruiting,
 parent_id,
 CASE
 	WHEN sub1_id IS NULL THEN 0
@@ -79,6 +80,12 @@ func (r *GuildRepository) RemoveGuildFromAlliance(allianceID, guildID, subGuild1
 	return err
 }
 
+// SetAllianceRecruiting updates whether an alliance is accepting applications.
+func (r *GuildRepository) SetAllianceRecruiting(allianceID uint32, recruiting bool) error {
+	_, err := r.db.Exec("UPDATE guild_alliances SET recruiting=$1 WHERE id=$2", recruiting, allianceID)
+	return err
+}
+
 // scanAllianceWithGuilds scans an alliance row and populates its guild data.
 func (r *GuildRepository) scanAllianceWithGuilds(rows *sqlx.Rows) (*GuildAlliance, error) {
 	alliance := &GuildAlliance{}