fix(config): default API URLs to https schweitz.net domains

Browser clients run on machines other than the host, and the homelab is
retiring direct LAN IP:port access (ports move to loopback behind NPM),
so the 192.168.86.149 defaults would stop working. The public domains
work from anywhere; LAN clients bypass Authentik via source-IP rules.
LAN development can still override via --dart-define.

Portainer (9000) and Netdata (19999) defaults are left unchanged: no
*.schweitz.net proxy hosts exist for those services yet.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

CHANGELOG.md

@@ -7,6 +7,13 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+
+- Default Core API and Tatlock API URLs now use the public domains
+  `https://api.schweitz.net` and `https://tatlock.schweitz.net` (previously LAN
+  `http://192.168.86.149:8083`/`:8000`), so default builds require OIDC auth;
+  override via `--dart-define` for direct LAN development
+
 ## [1.6.0] - 2026-01-08
 
 ### Added