fix(admin): list all masters and dedupe EC file counts in dashboard (#9093)

* fix(admin): list all masters and dedupe EC file counts in dashboard

Dashboard -> Master Nodes only ever showed the currently connected master
because getMasterNodesStatus hard-coded a single entry. Replace it with a
RaftListClusterServers call that returns every master in the raft group and
tags the real leader, falling back to the current master only if the raft
call fails.

Buckets -> Object Store Buckets could render 0 objects for a bucket backed
by an EC volume. Every shard holder reports the same whole-volume
file_count (read from the replicated .ecx), so the first-seen value wins;
if that first node had not yet finished loading .ecx it reported 0 and
pinned the aggregate at 0. Take the max across reporting nodes instead.

The dashboard header total_files also dropped after volumes were converted
to erasure coding because getTopologyViaGRPC never folded EC file_count
into topology.TotalFiles. Aggregate it with the same max/sum dedupe.

* fix(admin): address PR review comments

- bound RaftListClusterServers with a 3s timeout so the dashboard endpoint
  cannot hang on a stalled master
- pre-validate raft addresses with net.SplitHostPort before calling
  pb.GrpcAddressToServerAddress, which otherwise glog.Fatalf's on a
  malformed entry and would crash the admin process
- when raft is unreachable, mark the fallback master as not-leader rather
  than claiming leadership the code cannot verify
- warn when summed EC delete_count exceeds file_count while folding into
  topology.TotalFiles, matching collectCollectionStats

* fix(admin): distinguish empty raft response from RPC failure

When RaftListClusterServers returns successfully with no servers, raft is
not initialized (standalone/non-raft cluster), so the single fallback
master is the leader. Only treat the fallback as a non-leader when the
RPC actually failed.

* fix(admin): remove misleading Objects column from S3 buckets page

The bucket "Objects" column displayed needle counts from volume
collection stats, not actual S3 object counts. This is confusing
because a single S3 object can span multiple needles (multipart
uploads, versions) and the count is inaccurate for EC volumes.

Remove the ObjectCount field from S3Bucket, the Objects table column,
the sort-by-objects handler, the detail-view row, and both CSV export
references.

* fix(admin): correct cell indexes in fallback bucket CSV export

After the Objects column was removed, the fallback CSV exporter in
admin.js still used stale cell indexes: cells[1] mapped to Owner
(not Created), cells[2] to Created (not Size), cells[3] to Logical
Size (not Quota). Align all indexes with the current table column
order and include Owner, Logical Size, and Physical Size.

weed/admin/static/js/admin.js

@@ -583,21 +583,23 @@ function exportBucketList() {
 
         return {
             name: cells[0].textContent.trim(),
-            created: cells[1].textContent.trim(),
-            objects: cells[2].textContent.trim(),
-            size: cells[3].textContent.trim(),
-            quota: cells[4].textContent.trim()
+            owner: cells[1].textContent.trim(),
+            created: cells[2].textContent.trim(),
+            logicalSize: cells[3].textContent.trim(),
+            physicalSize: cells[4].textContent.trim(),
+            quota: cells[5].textContent.trim()
         };
     }).filter(item => item !== null);
 
     // Convert to CSV
     const csv = [
-        ['Name', 'Created', 'Objects', 'Size', 'Quota'].join(','),
+        ['Name', 'Owner', 'Created', 'Logical Size', 'Physical Size', 'Quota'].join(','),
         ...data.map(row => [
             row.name,
+            row.owner,
             row.created,
-            row.objects,
-            row.size,
+            row.logicalSize,
+            row.physicalSize,
             row.quota
         ].join(','))
     ].join('\n');