fix(ecstore): remove reachable panics in tiering, replication, and heal paths (#4205)

* fix(ecstore): remove reachable panics in tiering, replication, and heal paths

- Parse x-amz-expiration leniently in tier PUT responses; any lifecycle
  rule on the remote tier bucket returns an RFC1123 date that the previous
  ISO8601 unwrap turned into a panic of the ILM transition worker
- Skip invalid user-metadata header values (with a warning) when building
  tier and replication PUT headers instead of panicking on non-ASCII input
- Heal: tolerate absent data_dir for delete markers and remote objects
- transition_object: don't unwrap version_id on unversioned buckets when
  recording partial writes for offline disks
- Admin server info: use port_or_known_default() so default-port (80/443)
  endpoints don't panic is_server_resolvable
- Tier ListObjectsV2 client: decode response body with from_utf8_lossy
- walk_internal: log merge_entry_channels errors instead of dropping them

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* fix(ecstore): fail heal explicitly when data_dir is missing

Address review feedback: unwrap_or_default() silently substituted a nil
UUID when latest metadata lacked data_dir. Delete markers and remote
objects legitimately have no data_dir and skip the data-heal block, but
for a regular object a missing data_dir means corrupt metadata — return
FileCorrupt with a descriptive log instead of building part paths under
a nil UUID directory.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

crates/ecstore/src/store/list_objects.rs

@@ -1883,7 +1883,14 @@ impl ECStore {
             .instrument(tracing::Span::current()),
         );
 
-        tokio::spawn(async move { merge_entry_channels(rx, inputs, merge_tx, 1).await }.instrument(tracing::Span::current()));
+        tokio::spawn(
+            async move {
+                if let Err(err) = merge_entry_channels(rx, inputs, merge_tx, 1).await {
+                    error!("merge_entry_channels err {:?}", err)
+                }
+            }
+            .instrument(tracing::Span::current()),
+        );
 
         let walk_started = std::time::Instant::now();
         let walk_results = join_all(futures).await;
@@ -2952,7 +2959,14 @@ impl Sets {
             .instrument(tracing::Span::current()),
         );
 
-        tokio::spawn(async move { merge_entry_channels(rx, inputs, merge_tx, 1).await }.instrument(tracing::Span::current()));
+        tokio::spawn(
+            async move {
+                if let Err(err) = merge_entry_channels(rx, inputs, merge_tx, 1).await {
+                    error!("merge_entry_channels err {:?}", err)
+                }
+            }
+            .instrument(tracing::Span::current()),
+        );
 
         let walk_started = std::time::Instant::now();
         let walk_results = join_all(futures).await;