fix

modules/server/containers/apps/favicon.nix

@@ -112,10 +112,31 @@ let
             or headers.get("X-Original-Host")
             or headers.get("Host", "")
         )
-        host = (host or "").split(",", 1)[0].split(":", 1)[0].strip().lower()
-        if APP_DOMAIN and host.endswith(f".{APP_DOMAIN}"):
-            return host[:-(len(APP_DOMAIN) + 1)]
-        return host
+        return (host or "").split(",", 1)[0].split(":", 1)[0].strip().lower().rstrip(".")
+
+    def _host_candidates(host):
+        candidates = []
+
+        def add(candidate):
+            if candidate and candidate not in candidates:
+                candidates.append(candidate)
+
+        add(host)
+        if APP_DOMAIN:
+            suffix = f".{APP_DOMAIN}"
+            if host.endswith(suffix):
+                add(host[: -len(suffix)].rstrip("."))
+        if "." in host:
+            add(host.split(".", 1)[0])
+
+        return candidates
+
+    def _profile_for_host(host):
+        for candidate in _host_candidates(host):
+            profile = MAPPINGS.get(candidate)
+            if profile:
+                return candidate, profile
+        return None, DEFAULT_PROFILE
 
     def _replace_svg_color(svg, attribute, color):
         if attribute in {"fill", "stroke"}:
@@ -194,7 +215,7 @@ let
 
         def _serve(self, include_body):
             host = _request_host(self.headers)
-            profile = MAPPINGS.get(host) or DEFAULT_PROFILE
+            matched_host, profile = _profile_for_host(host)
             if not profile:
                 self.send_error(404, "No favicon mapping for host")
                 return
@@ -209,6 +230,8 @@ let
                 self.send_response(304)
                 self.send_header("ETag", etag)
                 self.send_header("Cache-Control", CACHE_CONTROL)
+                self.send_header("X-Favicon-Host", host or "default")
+                self.send_header("X-Favicon-Mapping", matched_host or "default")
                 self.end_headers()
                 return
 
@@ -218,6 +241,8 @@ let
             self.send_header("Content-Length", str(len(payload)))
             self.send_header("Cache-Control", CACHE_CONTROL)
             self.send_header("ETag", etag)
+            self.send_header("X-Favicon-Host", host or "default")
+            self.send_header("X-Favicon-Mapping", matched_host or "default")
             self.end_headers()
             if include_body:
                 self.wfile.write(payload)