clawhdf5-remote, h5rs: URLs' credentials are never shown

Every RemoteError message and HttpStorage's Debug output held the URL as
given, with any user:password@ and the query string — for a presigned
S3/GCS/Azure URL, its signature or token. An application logging the
error leaked the credential.

- New clawhdf5_remote::redact_url: no userinfo, no fragment, query values
  replaced by REDACTED (plain key names kept).
- HttpStorage formats every message with the redacted URL, and scrubs the
  URL's secret parts from errors of the HTTP client (whose texts can echo
  the URI); Debug shows the redacted URL. storage_for_url's and the object
  store URL errors are redacted too. HttpStorage::url() still returns the
  URL as given, documented as not for logging.
- h5rs prints FILE arguments that are URLs redacted: in errors and in
  dump/stat/check/diff output.
- The test server can force a status and send a wrong Content-Range.

Tests: 404, 403 (at open and on a read), wrong Content-Range (at open and
on a read), no range support, encoded body, ETag change, timeout,
connection closed and bad scheme errors, Display and Debug, contain none
of the secrets; h5rs likewise for every subcommand.

Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>

crates/clawhdf5-tools/src/dump.rs

@@ -98,6 +98,7 @@ pub fn run(args: &mut Args, out: &mut Out) -> std::io::Result<i32> {
         problems: 0,
         paths: OnceCell::new(),
     };
+    let file = crate::h5::shown(&file);
     let fname = std::path::Path::new(&file)
         .file_name()
         .map(|s| s.to_string_lossy().into_owned())