Prefer HTTPS site URL: fix first-open race + per-project HTTP/HTTPS preference

[Unthred]

Problem: status panel can lock onto http://localhost:5154 when the launch profile also has HTTPS because the first Kestrel listen line / first open port wins and polling stops.

Goal:

1. Do not permanently prefer the first HTTP listen endpoint when a higher-priority profile URL exists.
2. Per-project preference: Auto (prefer HTTPS) | HTTPS | HTTP.
3. Settings UI near Launch profile; document in SETTINGS.md.

Related: #57 / PR #58 canonical URL work.