sing-box: bump to 1.13.18 without Naive outbound support

sing-box: bump to 1.13.18 without Naive outbound support

This patch updates sing-box from 1.12.22 to 1.13.18.

Upstream release information:
https://github.com/SagerNet/sing-box/releases/tag/v1.13.0
https://github.com/SagerNet/sing-box/releases/tag/v1.13.18

Scope note:

The upstream Naive outbound feature is intentionally not enabled in this update.
Naive outbound requires additional build system integration because it depends on
Chromium Network Stack (Cronet). Depending on target and build mode, it requires
either the Cronet runtime library or a Chromium-based toolchain.
Upstream documentation:
https://sing-box.sagernet.org/configuration/outbound/naive/#structure

Changes:

1. Add upstream linker flags and compatibility build tags

Add linker flags required by the sing-box upstream release build:
- -checklinkname=0

Documentation:
https://sing-box.sagernet.org/installation/build-from-source/#linker-flags

-checklinkname=0 is required by the sing-box 1.13.x build configuration due to its use of
low-level go:linkname functionality and the stricter linkname validation in newer Go toolchains.

Add upstream compatibility build tags required by sing-box 1.13.x:
- badlinkname
- tfogo_checklinkname0

These tags are part of the upstream sing-box release build configuration:
https://sing-box.sagernet.org/installation/build-from-source/#build-tags

2. Add optional CCM and OCM build options

Add new optional OpenWrt configuration options:
- CONFIG_SINGBOX_WITH_CCM
  Build with Claude Code Multiplexer service support
- CONFIG_SINGBOX_WITH_OCM
  Build with OpenAI Codex Multiplexer service support

Both options are disabled by default and are only enabled when explicitly
selected by the user.

The corresponding upstream build tags are:
- with_ccm
- with_ocm

Documentation: https://sing-box.sagernet.org/installation/build-from-source/#build-tags
Signed-off-by: Sergei S. <redacted>