fix: use net.SplitHostPort in stripHostPort to correctly handle IPv6 hosts

[Copilot]

stripHostPort used a manual heuristic (checking for [) to detect IPv6 addresses, which caused it to leave the port in place for bracketed IPv6 hosts with ports (e.g. [::1]:5244), breaking virtual host matching.

Changes

• server/static/static.go: Replace manual string parsing in stripHostPort with net.SplitHostPort, which correctly handles all host header formats. Falls back to returning the host as-is when no port is present.

// Before — [::1]:5244 returned unchanged (port not stripped)
func stripHostPort(host string) string {
    if idx := strings.LastIndex(host, ":"); idx != -1 {
        if !strings.Contains(host, "[") {
            return host[:idx]
        }
    }
    return host
}

// After — correctly handles IPv4, IPv6 bracketed, and bare hosts
func stripHostPort(host string) string {
    h, _, err := net.SplitHostPort(host)
    if err != nil {
        return host
    }
    return h
}

Input	Before	After
[::1]:5244	[::1]:5244 ❌	::1 ✅
example.com:8080	example.com ✅	example.com ✅
192.168.1.1:8080	192.168.1.1 ✅	192.168.1.1 ✅
example.com	example.com ✅	example.com ✅

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