fix(fail2ban): fix banning regression and Docker zero-jail issue

- DockerEntrypoint.sh: create jail.d/filter.d/action.d config files
  before starting fail2ban so Docker containers no longer start with
  0 active jails (fixes #4134)

- x-ui.sh create_iplimit_jails: lower maxretry from 2 to 1 so
  fail2ban bans on the first log entry; with maxretry=2 and the
  partitionLiveIps logic the second occurrence could arrive after the
  32 s findtime window, silently preventing any ban (fixes #4163)

- x-ui.sh: fix datepattern (%%Y -> %Y) so fail2ban parses the Go
  log timestamp correctly instead of looking for a literal %%Y string

- x-ui.sh / DockerEntrypoint.sh: fix date command in actionban /
  actionunban echo (%%Y -> %Y) so the ban log records actual dates

- check_client_ip_job.go: replace log.SetOutput / log.SetFlags on
  the global standard-library logger with a local log.New instance,
  eliminating the dangling closed-file-handle between calls and
  stopping unrelated stdlib log output from polluting 3xipl.log

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

DockerEntrypoint.sh

@@ -1,7 +1,61 @@
 #!/bin/sh
 
-# Start fail2ban
-[ $XUI_ENABLE_FAIL2BAN == "true" ] && fail2ban-client -x start
+# Start fail2ban with the 3x-ipl jail
+if [ "$XUI_ENABLE_FAIL2BAN" = "true" ]; then
+    LOG_FOLDER="${XUI_LOG_FOLDER:-/var/log/x-ui}"
+    mkdir -p "$LOG_FOLDER"
+    touch "$LOG_FOLDER/3xipl.log" "$LOG_FOLDER/3xipl-banned.log"
+
+    mkdir -p /etc/fail2ban/jail.d /etc/fail2ban/filter.d /etc/fail2ban/action.d
+
+    cat > /etc/fail2ban/jail.d/3x-ipl.conf << EOF
+[3x-ipl]
+enabled=true
+backend=auto
+filter=3x-ipl
+action=3x-ipl
+logpath=$LOG_FOLDER/3xipl.log
+maxretry=1
+findtime=32
+bantime=30m
+EOF
+
+    cat > /etc/fail2ban/filter.d/3x-ipl.conf << 'EOF'
+[Definition]
+datepattern = ^%Y/%m/%d %H:%M:%S
+failregex   = \[LIMIT_IP\]\s*Email\s*=\s*<F-USER>.+</F-USER>\s*\|\|\s*Disconnecting OLD IP\s*=\s*<ADDR>\s*\|\|\s*Timestamp\s*=\s*\d+
+ignoreregex =
+EOF
+
+    cat > /etc/fail2ban/action.d/3x-ipl.conf << EOF
+[INCLUDES]
+before = iptables-allports.conf
+
+[Definition]
+actionstart = <iptables> -N f2b-<name>
+              <iptables> -A f2b-<name> -j <returntype>
+              <iptables> -I <chain> -p <protocol> -j f2b-<name>
+
+actionstop = <iptables> -D <chain> -p <protocol> -j f2b-<name>
+             <actionflush>
+             <iptables> -X f2b-<name>
+
+actioncheck = <iptables> -n -L <chain> | grep -q 'f2b-<name>[ \t]'
+
+actionban = <iptables> -I f2b-<name> 1 -s <ip> -j <blocktype>
+            echo "\$(date +"%Y/%m/%d %H:%M:%S")   BAN   [Email] = <F-USER> [IP] = <ip> banned for <bantime> seconds." >> $LOG_FOLDER/3xipl-banned.log
+
+actionunban = <iptables> -D f2b-<name> -s <ip> -j <blocktype>
+              echo "\$(date +"%Y/%m/%d %H:%M:%S")   UNBAN   [Email] = <F-USER> [IP] = <ip> unbanned." >> $LOG_FOLDER/3xipl-banned.log
+
+[Init]
+name = default
+protocol = tcp
+chain = INPUT
+EOF
+
+    fail2ban-client -x start
+fi
 
 # Run x-ui
 exec /app/x-ui