feat(server): INGEST_WING_RESOLVE=1 wires the wing resolver into the watcher (#205 S3)

Off by default (retired layout unchanged). On: eligibility from
classification.yaml, local ingest LLM as classifier, BM25 as cross-check,
INGEST_WING_THRESHOLD (default 0.9, rejected outside [0,1]). Build failure
is fatal when explicitly enabled.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

ingestion/cmd/wingbacktest/main.go

@@ -24,8 +24,6 @@ import (
 	"github.com/mathiasbq/hyperguild/ingestion/internal/wing"
 )
 
-var legacyDirs = map[string]bool{"concepts": true, "entities": true, "sources": true}
-
 func main() {
 	brain := flag.String("brain", "/var/lib/supervisor/brain", "brain directory (read only)")
 	wingsFlag := flag.String("wings", "", "comma-separated wings to sample pages FROM (must be wings you would allow)")
@@ -42,7 +40,7 @@ func main() {
 }
 
 func run(brain string, sampleWings []string, perWing int, llmURL, model string, seed int64) error {
-	known, err := knownWings(brain)
+	known, err := wing.KnownWings(brain)
 	if err != nil {
 		return err
 	}
@@ -112,30 +110,6 @@ func report(samples []wing.Sample, per map[string][]wing.Sample) {
 	}
 }
 
-// knownWings lists wiki/<wing> dirs that hold hall subdirectories, skipping
-// the retired legacy layout.
-func knownWings(brain string) ([]string, error) {
-	entries, err := os.ReadDir(filepath.Join(brain, "wiki"))
-	if err != nil {
-		return nil, fmt.Errorf("list wings: %w", err)
-	}
-	var out []string
-	for _, e := range entries {
-		if !e.IsDir() || legacyDirs[e.Name()] {
-			continue
-		}
-		subs, _ := os.ReadDir(filepath.Join(brain, "wiki", e.Name()))
-		for _, s := range subs {
-			if s.IsDir() {
-				out = append(out, e.Name())
-				break
-			}
-		}
-	}
-	sort.Strings(out)
-	return out, nil
-}
-
 func listPages(brain, w string) ([]string, error) {
 	var out []string
 	root := filepath.Join(brain, "wiki", w)