mach: build+tools: allow address and port of http server be configurable

for wasm

MACH_ADDRESS and MACH_PORT environment variable are added.

tools/http-server.zig

@@ -12,14 +12,23 @@ pub fn main() !u8 {
     const args = try std.process.argsAlloc(allocator);
     defer std.process.argsFree(allocator, args);
 
-    std.debug.print("Served at http://127.0.0.1:8000/{s}.html\n", .{args[1]});
+    if (args.len < 4) {
+        std.debug.print("Usage: http-server <application-name> <address> <port>\n", .{});
+        return 0;
+    }
+
+    const application_name = args[1];
+    const address = args[2];
+    const port = try std.fmt.parseUnsigned(u16, args[3], 10);
+
+    std.debug.print("Served at http://{s}:{}/{s}.html\n", .{ address, port, application_name });
 
     try file_server.init(allocator, .{ .dir_path = "." });
     defer file_server.deinit();
 
     try http.listenAndServe(
         allocator,
-        try std.net.Address.parseIp("127.0.0.1", 8000),
+        try std.net.Address.parseIp(address, port),
         {},
         file_server.serve,
     );