feat(server-ng): honor [http.cors] config on the HTTP listener (#3646)

Author: hubcio

core/server-ng/Cargo.toml

@@ -73,7 +73,6 @@ ignored = [
     "strum",
     "sysinfo",
     "tempfile",
-    "tower-http",
     "tracing-appender",
     "tracing-opentelemetry",
     "ulid",

core/server-ng/config.toml

@@ -65,19 +65,24 @@ enabled = true
 allowed_methods = ["GET", "POST", "PUT", "DELETE"]
 
 # Defines which origins are permitted to make cross-origin requests.
-# An asterisk "*" allows all origins. Specific domains can be listed to restrict access.
+# An asterisk "*" as the first entry allows all origins (any entries after it
+# are ignored); "*" in any other position fails the config. Specific domains
+# can be listed to restrict access.
 allowed_origins = ["*"]
 
 # Lists allowed headers that can be used in CORS requests.
 # For example, ["content-type"] permits only the content-type header.
 allowed_headers = ["content-type", "authorization"]
 
 # Headers that browsers are allowed to access in CORS responses.
-# An empty array means no additional headers are exposed to browsers.
-exposed_headers = [""]
+# `x-iggy-view` carries the current VSR view number; exposing it lets browser
+# clients read it on cross-origin responses.
+exposed_headers = ["x-iggy-view"]
 
 # Determines if credentials like cookies or HTTP auth can be included in CORS requests.
-# `true` allows credentials to be included, useful for authenticated sessions.
+# `true` allows credentials to be included, useful for authenticated sessions;
+# it requires explicit (non-wildcard) allowed_origins, allowed_headers, and
+# exposed_headers.
 # `false` prevents credentials, enhancing privacy and security.
 allow_credentials = false