fix(lore): embed-rebuild refuses when no embedder is wired

internal/lore/embed_rebuild_cmd.go

@@ -66,13 +66,20 @@ var EmbedRebuildCommand = &command.Command[EmbedRebuildInput, EmbedRebuildOutput
 			}, nil
 		}
 
-		// Use a NullEmbedder as placeholder when no real embedder is wired
-		// into the CLI deps yet (QUEST-212 wires the production embedder).
-		// For now the rebuild still performs the reset (zeroes coverage_num,
-		// flips states to pending) which is the user-visible guarantee.
-		e := embed.NewNullEmbedder()
+		ed := embedFromDeps(ctx, d)
+		if !ed.Enabled() {
+			return EmbedRebuildOutput{
+				ProjectID: pid,
+				Disabled:  true,
+				Reason:    "embedder runtime is not wired into this surface; embed-rebuild cannot encode and will not wipe existing vectors",
+			}, nil
+		}
 
-		modelID := report.ModelID
+		e := ed.Embedder
+		modelID := ed.ModelID
+		if modelID == "" {
+			modelID = report.ModelID
+		}
 		if modelID == "" {
 			modelID = string(MetaEmbedderModelID)
 		}

internal/lore/embed_rebuild_test.go

@@ -0,0 +1,186 @@
+package lore
+
+import (
+	"context"
+	"database/sql"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"github.com/mathomhaus/guild/internal/lore/embed"
+	"github.com/mathomhaus/guild/internal/storage"
+)
+
+const (
+	embedRebuildTestModelID = "test-model"
+	embedRebuildFakeDim     = 384
+)
+
+type embedRebuildFakeEmbedder struct{}
+
+func (embedRebuildFakeEmbedder) Embed(_ context.Context, text string) ([]float32, error) {
+	vec := make([]float32, embedRebuildFakeDim)
+	seed := float32(len(text)%7 + 1)
+	for i := range vec {
+		vec[i] = seed + float32(i%5)/10
+	}
+	return vec, nil
+}
+
+func (embedRebuildFakeEmbedder) Dimension() int {
+	return embedRebuildFakeDim
+}
+
+func TestEmbedRebuild_RefusesWhenEmbedderNotWired(t *testing.T) {
+	ctx := context.Background()
+	dbPath, db := newEmbedRebuildTestDB(t, "proj")
+	enableEmbedRebuildMeta(t, db)
+	entryIDs := seedEmbedRebuildEntries(t, ctx, db, "proj")
+	insertEmbedRebuildVectors(t, ctx, db, entryIDs)
+
+	before := countEmbedRebuildVectors(t, ctx, db)
+	if before == 0 {
+		t.Fatal("test setup did not write initial vectors")
+	}
+
+	deps := stubCommandDeps(nil)
+	deps.OpenDB = func(ctx context.Context) (*sql.DB, error) {
+		return storage.Open(ctx, dbPath)
+	}
+	deps.ResolveProj = func(_ context.Context, _ string) (string, error) {
+		return "proj", nil
+	}
+
+	out, err := EmbedRebuildCommand.Handler(ctx, deps, EmbedRebuildInput{})
+	if err != nil {
+		t.Fatalf("embed-rebuild: %v", err)
+	}
+	if !out.Disabled {
+		t.Fatalf("Disabled = false, want true")
+	}
+	if out.Reason == "" {
+		t.Fatal("Reason is empty")
+	}
+
+	after := countEmbedRebuildVectors(t, ctx, db)
+	if after != before {
+		t.Fatalf("vector rows after refusal = %d, want %d", after, before)
+	}
+}
+
+func TestEmbedRebuild_HappyPathWithWiredEmbedder(t *testing.T) {
+	ctx := context.Background()
+	dbPath, db := newEmbedRebuildTestDB(t, "proj")
+	enableEmbedRebuildMeta(t, db)
+	seedEmbedRebuildEntries(t, ctx, db, "proj")
+
+	deps := stubCommandDeps(&EmbedDeps{
+		Embedder: embedRebuildFakeEmbedder{},
+		ModelID:  embedRebuildTestModelID,
+	})
+	deps.OpenDB = func(ctx context.Context) (*sql.DB, error) {
+		return storage.Open(ctx, dbPath)
+	}
+	deps.ResolveProj = func(_ context.Context, _ string) (string, error) {
+		return "proj", nil
+	}
+
+	out, err := EmbedRebuildCommand.Handler(ctx, deps, EmbedRebuildInput{})
+	if err != nil {
+		t.Fatalf("embed-rebuild: %v", err)
+	}
+	if out.Disabled {
+		t.Fatalf("Disabled = true, want false: %s", out.Reason)
+	}
+	if out.Encoded == 0 {
+		t.Fatal("Encoded = 0, want > 0")
+	}
+	if got := countEmbedRebuildVectors(t, ctx, db); got != out.Encoded {
+		t.Fatalf("vector rows = %d, want encoded count %d", got, out.Encoded)
+	}
+}
+
+func newEmbedRebuildTestDB(t *testing.T, projectID string) (string, *sql.DB) {
+	t.Helper()
+	ctx := context.Background()
+	dbPath := filepath.Join(t.TempDir(), "lore.db")
+	db, err := storage.Open(ctx, dbPath)
+	if err != nil {
+		t.Fatalf("storage.Open: %v", err)
+	}
+	t.Cleanup(func() { _ = db.Close() })
+	if err := storage.MigrateTo(ctx, db, "test", nil); err != nil {
+		t.Fatalf("storage.MigrateTo: %v", err)
+	}
+	if _, err := db.ExecContext(ctx,
+		`INSERT INTO projects (id, path) VALUES (?, ?)`,
+		projectID, "/fake/"+projectID,
+	); err != nil {
+		t.Fatalf("insert project %q: %v", projectID, err)
+	}
+	return dbPath, db
+}
+
+func enableEmbedRebuildMeta(t *testing.T, db *sql.DB) {
+	t.Helper()
+	ctx := context.Background()
+	for _, kv := range []struct {
+		key   string
+		value string
+	}{
+		{"embedder_state", string(embed.EmbedderStateEnabled)},
+		{"embedder_model_id", embedRebuildTestModelID},
+	} {
+		if _, err := db.ExecContext(ctx,
+			`INSERT INTO meta (key, value) VALUES (?, ?)
+			 ON CONFLICT(key) DO UPDATE SET value = excluded.value`,
+			kv.key, kv.value,
+		); err != nil {
+			t.Fatalf("set meta %s: %v", kv.key, err)
+		}
+	}
+}
+
+func seedEmbedRebuildEntries(t *testing.T, ctx context.Context, db *sql.DB, projectID string) []int64 {
+	t.Helper()
+	now := time.Date(2026, 5, 20, 12, 0, 0, 0, time.UTC)
+	entryIDs := make([]int64, 0, 2)
+	for i, title := range []string{"first rebuild entry", "second rebuild entry"} {
+		res, err := Inscribe(ctx, db, &InscribeParams{
+			ProjectID: projectID,
+			Kind:      KindObservation,
+			Title:     title,
+			Summary:   title + " has deterministic content for vector rebuild testing.",
+			Topic:     "embed-rebuild",
+			Now:       now.Add(time.Duration(i) * time.Minute),
+		})
+		if err != nil {
+			t.Fatalf("inscribe %q: %v", title, err)
+		}
+		entryIDs = append(entryIDs, res.Entry.ID)
+	}
+	return entryIDs
+}
+
+func insertEmbedRebuildVectors(t *testing.T, ctx context.Context, db *sql.DB, entryIDs []int64) {
+	t.Helper()
+	for _, entryID := range entryIDs {
+		if _, err := db.ExecContext(ctx,
+			`INSERT INTO lore_vectors
+			   (entry_id, model_id, dim, vec, encoded_at, content_hash)
+			 VALUES (?, ?, ?, ?, ?, ?)`,
+			entryID, embedRebuildTestModelID, 64, make([]byte, 64), time.Now().UTC().Unix(), "hash",
+		); err != nil {
+			t.Fatalf("insert lore_vectors for entry %d: %v", entryID, err)
+		}
+	}
+}
+
+func countEmbedRebuildVectors(t *testing.T, ctx context.Context, db *sql.DB) int64 {
+	t.Helper()
+	var count int64
+	if err := db.QueryRowContext(ctx, `SELECT COUNT(*) FROM lore_vectors`).Scan(&count); err != nil {
+		t.Fatalf("count lore_vectors: %v", err)
+	}
+	return count
+}