fix(mcp): keep path anchoring when the server has no multiIndexer

internal/mcp/id_resolve.go

@@ -91,14 +91,21 @@ func (s *Server) resolveSymbolID(ctx context.Context, id string) string {
 	if id == "" || s.graph == nil || s.graph.GetNode(id) != nil {
 		return id
 	}
-	if s.multiIndexer == nil {
-		return id
-	}
-	cwd := SessionCWDFromContext(ctx)
-	if cwd != "" {
-		if _, _, prefix, ok := s.multiIndexer.ScopeForCWD(cwd); ok && prefix != "" {
-			if cand := prefix + "/" + id; s.graph.GetNode(cand) != nil {
-				return cand
+	// The cwd rung needs the multi-repo index to map a directory to a repo
+	// prefix; the graphRelID rung below does not. Returning early on a nil
+	// multiIndexer skipped both, which cost a server built without
+	// MultiRepoOptions (cmd/gortex eval_recall.go, eval_server.go) the
+	// separator normalization graphPathSpelling exists to provide: on Windows
+	// the stored id is `pkga\a.go::Foo` while every agent writes
+	// `pkga/a.go::Foo`, and the tool answered "symbol not found" for an
+	// indexed symbol.
+	if s.multiIndexer != nil {
+		cwd := SessionCWDFromContext(ctx)
+		if cwd != "" {
+			if _, _, prefix, ok := s.multiIndexer.ScopeForCWD(cwd); ok && prefix != "" {
+				if cand := prefix + "/" + id; s.graph.GetNode(cand) != nil {
+					return cand
+				}
 			}
 		}
 	}

internal/mcp/id_resolve_test.go

@@ -2,6 +2,7 @@ package mcp
 
 import (
 	"context"
+	"path/filepath"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -22,6 +23,40 @@ func nameResolveServer(t *testing.T) *Server {
 	return s
 }
 
+// TestResolveSymbolID_WithoutMultiIndexer_StillAnchorsThePath pins the rung
+// order inside resolveSymbolID: the cwd rung needs the multi-repo index to map
+// a directory to a repo prefix, the graphRelID rung does not. Returning early
+// on a nil multiIndexer skipped both, so a server built without
+// MultiRepoOptions — cmd/gortex's eval_recall.go and eval_server.go — lost path
+// anchoring entirely.
+//
+// The absolute-path spelling is deliberate: it exercises the rung on every
+// platform, so the linux/macos matrix protects this. On Windows the same rung
+// additionally reconciles the separator, which is what graphPathSpelling exists
+// for — the store holds `pkga\a.go::Foo` while every agent writes
+// `pkga/a.go::Foo`, and move_symbol answered "symbol not found" for an indexed
+// symbol.
+func TestResolveSymbolID_WithoutMultiIndexer_StillAnchorsThePath(t *testing.T) {
+	srv, dir := setupMoveInlineRepo(t, map[string]string{
+		"pkga/a.go": "package pkga\n\nfunc Foo() int { return 42 }\n",
+	})
+	require.Nil(t, srv.multiIndexer, "fixture must exercise the nil-multiIndexer path")
+
+	var stored string
+	for _, n := range srv.graph.FindNodesByName("Foo") {
+		if n != nil && n.Kind == graph.KindFunction {
+			stored = n.ID
+		}
+	}
+	require.NotEmpty(t, stored, "fixture must index Foo")
+
+	absID := filepath.Join(dir, "pkga", "a.go") + "::Foo"
+	require.Nil(t, srv.graph.GetNode(absID), "the absolute spelling must not be a stored id")
+
+	assert.Equal(t, stored, srv.resolveSymbolID(context.Background(), absID),
+		"an absolute-path id must anchor back to the stored id without a multiIndexer")
+}
+
 func TestResolveNameToIDs(t *testing.T) {
 	s := nameResolveServer(t)
 	got := s.resolveNameToIDs("Bar")