[codex] add native Tailscale support to neo

[cadl]

Summary

• add native Tailscale connectivity through the pinned cadl/libts3ds v0.1.0 submodule
• start Tailscale when an auth key is configured or a persisted node state exists
• route libssh2 over the libts3ds TCP transport, supporting automatic direct, peer-relay, and DERP path selection
• preserve the neo branch's keychain bootstrap, fish terminal fixes, mascot states, and SELECT reconnect behavior
• reuse the active Tailscale node when SELECT reconnects the SSH session

Relationship to existing work

This PR targets the updated neo branch after #2 was merged. The keychain and fish terminal foundation originated in Fishason#6; this PR layers the 3DS-native Tailscale transport on top without adding the upstream-oriented branch history again.

libts3ds is maintained at https://github.com/cadl/libts3ds and is pinned to the libts3ds-v0.1.0 release.

Configuration

Setting tailscale_auth_key enables first-time registration. The default hostname is dssh-3ds and the default state path is sdmc:/3ds/3dssh/tailscale.state. A persisted state can start Tailscale without keeping an auth key in the config.

Build

The normal make command is unchanged, but the repository must be cloned recursively or initialized with:

git submodule update --init --recursive

The top-level Makefile builds libts3ds before linking DSSH.

Validation

• bash tools/test_config.sh
• bash tools/test_terminal.sh
• bash tools/test_ime.sh
• complete devkitARM build of libts3ds and 3dssh.3dsx

[chatgpt-codex-connector]

You have reached your Codex usage limits for code reviews. You can see your limits in the Codex usage dashboard.