Adds the HTTP redirect listener that redirects all plain HTTP requests to
the HTTPS equivalent URL. Each listener with http_port > 0 runs its own
redirect server on bind_addr:http_port.
- build_redirect_url: constructs https://{host}:{port}/{path}?{query},
omitting port 443 and stripping the host port from the Host header
- redirect_handler: axum handler returning 301 with Location header,
400 for missing/empty Host, 404 for ACME challenge paths
- redirect_router: creates axum Router with fallback handler
- start_http_redirect_listener: binds TCP and spawns redirect server
- ACME HTTP-01 challenge path returns 404 (placeholder for future)
- 19 unit tests for URL construction and host parsing
- 8 integration tests covering 301 redirect, 400 on missing Host,
port 443 omission, non-443 port inclusion, query preservation,
ACME challenge 404
glm-5.1
d893187c40