docs(catalogs): describe both bad-port failure modes accurately

The comment attributed both malformed-port cases to
http.client.InvalidURL. Only a non-numeric port raises that (when the
connection object is built); an out-of-range port constructs fine and
fails later in the socket layer. Measured:

  example.invalid:notaport -> http.client.InvalidURL: nonnumeric port
  example.invalid:65536    -> HTTPSConnection() OK, connect() fails

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: jawwad-ali

src/specify_cli/catalogs.py

@@ -76,8 +76,10 @@ def _validate_catalog_url(cls, url: str) -> None:
             hostname = parsed.hostname
             # Accessing ``port`` performs urllib's syntax/range validation;
             # ``hostname`` alone does not, so a non-numeric or out-of-range
-            # port would otherwise pass validation here and escape as a raw
-            # http.client.InvalidURL at fetch time.
+            # port would otherwise pass validation here and only fail later,
+            # at fetch time, as an error this module does not translate --
+            # a raw http.client.InvalidURL for a non-numeric port, and a
+            # socket-layer failure for one that is merely out of range.
             _ = parsed.port
         except ValueError:
             raise cls._error(f"Catalog URL is malformed: {url}") from None