"textual serve" binding to 0.0.0.0 is not accessible via any interface

[Orlando-Richards]

I'm looking to bind textual serve to all interfaces, so that it is accessible via any IP/hostname that can reach the server it's running on - so I can look at the application from my laptop, my demo system, or my CI platform without knowing which IP it will be contacted over.

The URL for the application content and websockets is currently "hard coded" to either the value of --url, or the combination of --hostand --port. Normally, I'd expect the URL to be relative to the address the client has put into their browser bar.

This patch delivers this - using the address from the request to construct the required url's "dynamically" based on the user's request:

diff --git a/textual_serve/server.py b/textual_serve/server.py
index 1234567..abcdefg 100644
--- a/textual_serve/server.py
+++ b/textual_serve/server.py
@@ -249,18 +249,18 @@ class Server:
         font_size = to_int(request.query.get("fontsize", "16"), 16)

         def get_url(route: str, **args) -> str:
-            """Get a URL from the aiohttp router."""
+            """Get a relative URL from the aiohttp router."""
             path = router[route].url_for(**args)
-            return f"{self.public_url}{path}"
+            return str(path)

         def get_websocket_url(route: str, **args) -> str:
-            """Get a URL with a websocket prefix."""
-            url = get_url(route, **args)
-
-            if self.public_url.startswith("https"):
-                return "wss:" + url.split(":", 1)[1]
-            else:
-                return "ws:" + url.split(":", 1)[1]
+            """Get a protocol-relative WebSocket URL from the incoming request."""
+            path = router[route].url_for(**args)
+            # Determine WebSocket protocol from the incoming request's scheme
+            scheme = request.scheme
+            ws_protocol = "wss" if scheme == "https" else "ws"
+            # Use protocol-relative URL that works with any hostname
+            return f"{ws_protocol}://{request.host}{path}"

         context = {
             "font_size": font_size,
--

Is this worth submitting as a PR?