fix: harden gateway auth defaults

CHANGELOG.md

@@ -43,6 +43,9 @@ Status: unreleased.
 - Slack: clear ack reaction after streamed replies. (#2044) Thanks @fancyboi999.
 - macOS: keep custom SSH usernames in remote target. (#2046) Thanks @algal.
 
+### Breaking
+- **BREAKING:** Gateway auth mode "none" is removed; gateway now requires token/password (Tailscale Serve identity still allowed).
+
 ### Fixes
 - Telegram: wrap reasoning italics per line to avoid raw underscores. (#2181) Thanks @YuriNachos.
 - Voice Call: enforce Twilio webhook signature verification for ngrok URLs; disable ngrok free tier bypass by default.
@@ -53,6 +56,7 @@ Status: unreleased.
 - Web UI: improve WebChat image paste previews and allow image-only sends. (#1925) Thanks @smartprogrammer93.
 - Security: wrap external hook content by default with a per-hook opt-out. (#1827) Thanks @mertcicekci0.
 - Gateway: default auth now fail-closed (token/password required; Tailscale Serve identity remains allowed).
+- Gateway: treat loopback + non-local Host connections as remote unless trusted proxy headers are present.
 - Onboarding: remove unsupported gateway auth "off" choice from onboarding/configure flows and CLI flags.
 
 ## 2026.1.24-3