feat(plugin): enhanced collection filtering for volume balance (#8620)

* feat(plugin): enhanced collection filtering for volume balance

Replace wildcard matching with three collection filter modes:
- ALL_COLLECTIONS (default): treat all volumes as one pool
- EACH_COLLECTION: run detection separately per collection
- Regex pattern: filter volumes by matching collection names

The EACH_COLLECTION mode extracts distinct collections from metrics
and calls Detection() per collection, sharing the maxResults budget
and clusterInfo (with ActiveTopology) across all calls.

* address PR review: fix wildcard→regexp replacement, optimize EACH_COLLECTION

* address nitpick: fail fast on config errors (invalid regex)

Add configError type so invalid collection_filter regex returns
immediately instead of retrying across all masters with the same
bad config. Transient errors still retry.

* address review: constants, unbounded maxResults, wildcard compat

- Define collectionFilterAll/collectionFilterEach constants to
  eliminate magic strings across handler and metrics code
- Fix EACH_COLLECTION budget loop to treat maxResults <= 0 as
  unbounded, matching Detection's existing semantics
- Treat "*" as ALL_COLLECTIONS for backward compat with wildcard

* address review: nil guard in EACH_COLLECTION grouping loop

* remove useless descriptor string test

weed/plugin/worker/volume_metrics.go

@@ -2,7 +2,9 @@ package pluginworker
 
 import (
 	"context"
+	"errors"
 	"fmt"
+	"regexp"
 	"sort"
 	"strings"
 	"time"
@@ -11,7 +13,6 @@ import (
 	"github.com/seaweedfs/seaweedfs/weed/glog"
 	"github.com/seaweedfs/seaweedfs/weed/pb"
 	"github.com/seaweedfs/seaweedfs/weed/pb/master_pb"
-	"github.com/seaweedfs/seaweedfs/weed/util/wildcard"
 	workertypes "github.com/seaweedfs/seaweedfs/weed/worker/types"
 	"google.golang.org/grpc"
 )
@@ -38,6 +39,11 @@ func collectVolumeMetricsFromMasters(
 
 		metrics, activeTopology, buildErr := buildVolumeMetrics(response, collectionFilter)
 		if buildErr != nil {
+			// Configuration errors (e.g. invalid regex) will fail on every master,
+			// so return immediately instead of masking them with retries.
+			if isConfigError(buildErr) {
+				return nil, nil, buildErr
+			}
 			glog.Warningf("Plugin worker failed to build metrics from master %s: %v", masterAddress, buildErr)
 			continue
 		}
@@ -93,7 +99,16 @@ func buildVolumeMetrics(
 		return nil, nil, err
 	}
 
-	patterns := wildcard.CompileWildcardMatchers(collectionFilter)
+	var collectionRegex *regexp.Regexp
+	trimmedFilter := strings.TrimSpace(collectionFilter)
+	if trimmedFilter != "" && trimmedFilter != collectionFilterAll && trimmedFilter != collectionFilterEach && trimmedFilter != "*" {
+		var err error
+		collectionRegex, err = regexp.Compile(trimmedFilter)
+		if err != nil {
+			return nil, nil, &configError{err: fmt.Errorf("invalid collection_filter regex %q: %w", trimmedFilter, err)}
+		}
+	}
+
 	volumeSizeLimitBytes := uint64(response.VolumeSizeLimitMb) * 1024 * 1024
 	now := time.Now()
 	metrics := make([]*workertypes.VolumeHealthMetrics, 0, 256)
@@ -103,7 +118,7 @@ func buildVolumeMetrics(
 			for _, node := range rack.DataNodeInfos {
 				for diskType, diskInfo := range node.DiskInfos {
 					for _, volume := range diskInfo.VolumeInfos {
-						if !wildcard.MatchesAnyWildcard(patterns, volume.Collection) {
+						if collectionRegex != nil && !collectionRegex.MatchString(volume.Collection) {
 							continue
 						}
 
@@ -148,6 +163,19 @@ func buildVolumeMetrics(
 	return metrics, activeTopology, nil
 }
 
+// configError wraps configuration errors that should not be retried across masters.
+type configError struct {
+	err error
+}
+
+func (e *configError) Error() string { return e.err.Error() }
+func (e *configError) Unwrap() error { return e.err }
+
+func isConfigError(err error) bool {
+	var ce *configError
+	return errors.As(err, &ce)
+}
+
 func masterAddressCandidates(address string) []string {
 	trimmed := strings.TrimSpace(address)
 	if trimmed == "" {