Restore the __Host- browser guarantees for the default secure deployment
without breaking plaintext/dev:
- DashboardServiceCollectionExtensions PostConfigure now resolves the cookie
name as: explicit MxGateway:Dashboard:CookieName override wins; else
__Host-MxGatewayDashboard when SecurePolicy==Always (RequireHttpsCookie
true); else the plain MxGatewayDashboard default. Guard: never apply the
__Host- prefix without Secure (browsers silently drop it).
- DashboardAuthenticationDefaults: add SecureCookieName const; keep the plain
CookieName as the non-secure fallback.
- Docs corrected to the actual conditional contract (five stale claims):
gateway.md, GatewayProcessDesign.md, ImplementationPlanGateway.md,
GatewayDashboardDesign.md, CLAUDE.md; GatewayConfiguration.md phrasing
tightened.
- Test: DashboardCookieOptionsTests asserts the name flips with
RequireHttpsCookie and that an explicit override wins.
Server build clean (0 warnings); Dashboard tests 149/149.
Claude-Session: https://claude.ai/code/session_01DMXXvNuPekkkrTEyPNxEkW
Joseph Doherty
7d42c85345