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/internal/wing/known_test.go

@@ -0,0 +1,29 @@
+package wing_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/mathiasbq/hyperguild/ingestion/internal/wing"
+)
+
+func TestKnownWings_ListsWingsWithHallsAndSkipsTheRetiredLayout(t *testing.T) {
+	dir := t.TempDir()
+	writePage(t, dir, "wiki/homelab/facts/a.md", "x")
+	writePage(t, dir, "wiki/tapir/decisions/b.md", "x")
+	writePage(t, dir, "wiki/concepts/c.md", "x")       // retired layout, a file directly under a legacy dir
+	writePage(t, dir, "wiki/sources/d.md", "x")        // retired layout
+	writePage(t, dir, "wiki/entities/e.md", "x")       // retired layout
+	writePage(t, dir, "wiki/loose-note.md", "x")       // a file, not a wing
+	writePage(t, dir, "wiki/emptywing/_index.md", "x") // a dir with no hall subdirectory
+	got, err := wing.KnownWings(dir)
+	require.NoError(t, err)
+	assert.Equal(t, []string{"homelab", "tapir"}, got)
+}
+
+func TestKnownWings_NoWikiDirIsAnError(t *testing.T) {
+	_, err := wing.KnownWings(t.TempDir())
+	assert.Error(t, err, "a brain without wiki/ must not look like a brain with no wings")
+}