fix(ec): blanket-clean every destination over the full shard range (#9512)

* fix(ec): blanket-clean every destination over the full shard range

The previous cleanup pass walked t.sources only, with the shard ids the
topology had reported at detection time. In the wild, a destination can
end up with EC shards mounted that the topology snapshot didn't list —
shards on a sibling disk that hadn't heartbeated, or shards left over
from a concurrent attempt's mount step. FindEcVolume still returns
true, so the next ReceiveFile trips the mounted-volume guard.

Cleanup now unions t.sources (with ShardIds) and t.targets and issues
unmount + delete over [0..totalShards-1] on each. Both RPCs are
idempotent on missing shards, so the wider sweep is free.

Two new tests cover the gap: shards mounted beyond what t.sources
lists, and a target-only destination with no source row.

* log(ec): include disk_id in EC unmount/delete/refusal log lines

The current logs identify the volume and shard but leave disk_id off,
which makes the cross-server cleanup story hard to follow when
multiple disks of one server hold pieces of the same volume:

  UnmountEcShards 4121.1                              -> add disk_id
  ec volume video-recordings_4121 shard delete [1 5]  -> add per-loc disk_id
  volume server X:Y deletes ec shards from 4121 [...] -> add disk_id
  ReceiveFile: ec volume 4121 is mounted; refusing... -> add disk_ids

ReceiveFile's refusal now names the disk_ids actually holding the
mount so operators can see whether the next cleanup pass needs to
target a sibling disk. Added Store.FindEcVolumeDiskIds /
Store::find_ec_volume_disk_ids as the supporting primitive.

Mirrored in seaweed-volume/src/ (unmount log in Store::unmount_ec_shard,
heartbeat delete log in diff_ec_shard_delta_messages, refusal in the
ReceiveFile handler).

* test(ec): stub VolumeEcShardsUnmount/Delete on the fake volume server

The plugin-worker EC tests boot a fake volume server that embeds
UnimplementedVolumeServerServer. After the worker started calling
VolumeEcShardsUnmount + VolumeEcShardsDelete pre-distribute, the
default Unimplemented response surfaced as fourteen "method not
implemented" errors and TestErasureCodingExecutionEncodesShards
failed. Both RPCs are no-ops here — nothing on the fake server has
mounted state or persisted shard files to remove.

weed/storage/store_ec.go

@@ -237,12 +237,12 @@ func (s *Store) UnmountEcShards(vid needle.VolumeId, shardId erasure_coding.Shar
 	location := s.Locations[diskId]
 
 	if deleted := location.UnloadEcShard(vid, shardId); deleted {
-		glog.V(0).Infof("UnmountEcShards %d.%d", vid, shardId)
+		glog.V(0).Infof("UnmountEcShards %d.%d disk_id:%d", vid, shardId, diskId)
 		s.DeletedEcShardsChan <- message
 		return nil
 	}
 
-	return fmt.Errorf("UnmountEcShards %d.%d not found on disk", vid, shardId)
+	return fmt.Errorf("UnmountEcShards %d.%d not found on disk %d", vid, shardId, diskId)
 }
 
 func (s *Store) findEcShard(vid needle.VolumeId, shardId erasure_coding.ShardId) (diskId uint32, shard *erasure_coding.EcVolumeShard, found bool) {
@@ -269,6 +269,20 @@ func (s *Store) FindEcVolume(vid needle.VolumeId) (*erasure_coding.EcVolume, boo
 	return nil, false
 }
 
+// FindEcVolumeDiskIds returns every disk_id on this store that has an
+// EcVolume entry for the given volume. Useful for diagnostic logging
+// when a single FindEcVolume hit hides which disk is actually holding
+// the mount (e.g., the ReceiveFile mounted-volume guard).
+func (s *Store) FindEcVolumeDiskIds(vid needle.VolumeId) []uint32 {
+	var ids []uint32
+	for diskId, location := range s.Locations {
+		if _, found := location.FindEcVolume(vid); found {
+			ids = append(ids, uint32(diskId))
+		}
+	}
+	return ids
+}
+
 // shardFiles is a list of shard files, which is used to return the shard locations
 func (s *Store) CollectEcShards(vid needle.VolumeId, shardFileNames []string) (ecVolume *erasure_coding.EcVolume, found bool) {
 	for _, location := range s.Locations {