fix(genesis-writer): keep sub-second precision on every emitted timestamp

cmd/genesis-writer/entities_comment.go

@@ -139,7 +139,7 @@ func (w *Writer) writeCommentPass(
 				EntityID:        c.EntityID,
 				EntityType:      c.EntityType,
 				TrackTimestampS: c.TrackTimestampS,
-				CreatedAt:       c.CreatedAt.UTC().Format(time.RFC3339),
+				CreatedAt:       c.CreatedAt.UTC().Format(time.RFC3339Nano),
 				IsMembersOnly:   c.IsMembersOnly,
 				VideoURL:        deref(c.VideoURL),
 				IsEdited:        c.IsEdited,
@@ -194,7 +194,7 @@ func (w *Writer) writeCommentReactions(ctx context.Context) error {
 			return cr, err
 		},
 		func(ctx context.Context, cr commentReaction) error {
-			metaJSON, err := json.Marshal(createdAtMeta{CreatedAt: cr.createdAt.UTC().Format(time.RFC3339)})
+			metaJSON, err := json.Marshal(createdAtMeta{CreatedAt: cr.createdAt.UTC().Format(time.RFC3339Nano)})
 			if err != nil {
 				return fmt.Errorf("marshal comment reaction metadata: %w", err)
 			}

cmd/genesis-writer/entities_comment_pin.go

@@ -74,7 +74,7 @@ func (w *Writer) writeCommentPins(ctx context.Context) error {
 		func(ctx context.Context, p sourceCommentPin) error {
 			metaJSON, err := json.Marshal(commentPinMetadata{
 				EntityID:  p.TrackID,
-				CreatedAt: p.PinnedAt.UTC().Format(time.RFC3339),
+				CreatedAt: p.PinnedAt.UTC().Format(time.RFC3339Nano),
 			})
 			if err != nil {
 				return fmt.Errorf("marshal comment pin metadata for track %d: %w", p.TrackID, err)

cmd/genesis-writer/entities_dashboard_wallet.go

@@ -39,7 +39,7 @@ func (w *Writer) writeDashboardWalletUsers(ctx context.Context) error {
 		func(ctx context.Context, d sourceDashboardWalletUser) error {
 			metaJSON, err := json.Marshal(dashboardWalletMetadata{
 				Wallet:    d.Wallet,
-				CreatedAt: d.CreatedAt.UTC().Format(time.RFC3339),
+				CreatedAt: d.CreatedAt.UTC().Format(time.RFC3339Nano),
 				IsDelete:  d.IsDelete,
 			})
 			if err != nil {

cmd/genesis-writer/entities_developer_app.go

@@ -59,7 +59,7 @@ func (w *Writer) writeDeveloperApps(ctx context.Context) error {
 				Description:      deref(d.Description),
 				ImageURL:         deref(d.ImageURL),
 				IsPersonalAccess: d.IsPersonalAccess,
-				CreatedAt:        d.CreatedAt.UTC().Format(time.RFC3339),
+				CreatedAt:        d.CreatedAt.UTC().Format(time.RFC3339Nano),
 			}
 			metaJSON, err := json.Marshal(meta)
 			if err != nil {
@@ -148,7 +148,7 @@ func (w *Writer) writeGrants(ctx context.Context) error {
 				IsRevoked:      g.IsRevoked,
 				IsApproved:     g.IsApproved,
 				GranteeAddress: g.GranteeAddress,
-				CreatedAt:      g.CreatedAt.UTC().Format(time.RFC3339),
+				CreatedAt:      g.CreatedAt.UTC().Format(time.RFC3339Nano),
 			})
 			if err != nil {
 				return fmt.Errorf("marshal grant metadata: %w", err)

cmd/genesis-writer/entities_email.go

@@ -97,7 +97,7 @@ func (w *Writer) writeEncryptedEmails(ctx context.Context) error {
 				EmailOwnerUserID: e.EmailOwnerUserID,
 				EncryptedEmail:   e.EncryptedEmail,
 				AccessGrants:     grants,
-				CreatedAt:        e.CreatedAt.UTC().Format(time.RFC3339),
+				CreatedAt:        e.CreatedAt.UTC().Format(time.RFC3339Nano),
 			}
 			metaJSON, err := json.Marshal(meta)
 			if err != nil {
@@ -165,7 +165,7 @@ func (w *Writer) writeEmailAccess(ctx context.Context) error {
 					GrantorUserID:   ea.grantorUserID,
 					EncryptedKey:    ea.encryptedKey,
 				}},
-				CreatedAt: ea.createdAt.UTC().Format(time.RFC3339),
+				CreatedAt: ea.createdAt.UTC().Format(time.RFC3339Nano),
 			})
 			if err != nil {
 				return fmt.Errorf("marshal email access metadata: %w", err)

cmd/genesis-writer/entities_event.go

@@ -50,13 +50,13 @@ func (w *Writer) writeEvents(ctx context.Context) error {
 			meta := eventMetadata{
 				EventType: e.EventType,
 				EntityID:  e.EntityID,
-				CreatedAt: e.CreatedAt.UTC().Format(time.RFC3339),
+				CreatedAt: e.CreatedAt.UTC().Format(time.RFC3339Nano),
 			}
 			if e.EntityType != nil {
 				meta.EntityType = *e.EntityType
 			}
 			if e.EndDate != nil {
-				meta.EndDate = e.EndDate.UTC().Format(time.RFC3339)
+				meta.EndDate = e.EndDate.UTC().Format(time.RFC3339Nano)
 			}
 			meta.EventData = unmarshalJSONB(e.EventData)
 

cmd/genesis-writer/entities_playlist.go

@@ -87,8 +87,8 @@ func preloadRemovedPlaylistTracks(ctx context.Context, db *pgxpool.Pool) (map[in
 		if err := rows.Scan(&playlistID, &r.TrackID, &createdAt, &updatedAt); err != nil {
 			return nil, err
 		}
-		r.CreatedAt = createdAt.UTC().Format(time.RFC3339)
-		r.UpdatedAt = updatedAt.UTC().Format(time.RFC3339)
+		r.CreatedAt = createdAt.UTC().Format(time.RFC3339Nano)
+		r.UpdatedAt = updatedAt.UTC().Format(time.RFC3339Nano)
 		m[playlistID] = append(m[playlistID], r)
 	}
 	return m, rows.Err()
@@ -180,7 +180,7 @@ func (w *Writer) writePlaylists(ctx context.Context) error {
 		},
 		func(ctx context.Context, p sourcePlaylist) error {
 			inner := playlistMetadataInner{
-				CreatedAt:              p.CreatedAt.UTC().Format(time.RFC3339),
+				CreatedAt:              p.CreatedAt.UTC().Format(time.RFC3339Nano),
 				PlaylistName:           deref(p.PlaylistName),
 				Description:            deref(p.Description),
 				IsAlbum:                p.IsAlbum,

cmd/genesis-writer/entities_social.go

@@ -44,7 +44,7 @@ type repostMeta struct {
 }
 
 func fmtCreatedAt(t time.Time) string {
-	return t.UTC().Format(time.RFC3339)
+	return t.UTC().Format(time.RFC3339Nano)
 }
 
 // --- Follows ---

cmd/genesis-writer/entities_track.go

@@ -143,7 +143,7 @@ type sourceTrack struct {
 // a column the writer forgets to carry is invisible in the output otherwise.
 func buildTrackMetadata(t sourceTrack, collaborators []int64) trackMetadataInner {
 	inner := trackMetadataInner{
-		CreatedAt:       t.CreatedAt.UTC().Format(time.RFC3339),
+		CreatedAt:       t.CreatedAt.UTC().Format(time.RFC3339Nano),
 		OwnerID:         t.OwnerID,
 		Title:           deref(t.Title),
 		Description:     deref(t.Description),
@@ -223,7 +223,10 @@ func fmtReleaseDate(t *time.Time) string {
 	if t == nil {
 		return ""
 	}
-	return t.UTC().Format(time.RFC3339)
+	// RFC3339Nano, not RFC3339: the plain layout has no fractional-second
+	// component, which silently rounded 26,129 tracks whose release_date
+	// carries microseconds down to the whole second.
+	return t.UTC().Format(time.RFC3339Nano)
 }
 
 func (w *Writer) writeTracks(ctx context.Context) error {
@@ -367,7 +370,7 @@ func (w *Writer) writeTrackDownloads(ctx context.Context) error {
 				City:      deref(d.City),
 				Region:    deref(d.Region),
 				Country:   deref(d.Country),
-				CreatedAt: d.CreatedAt.UTC().Format(time.RFC3339),
+				CreatedAt: d.CreatedAt.UTC().Format(time.RFC3339Nano),
 			}
 			metaJSON, err := json.Marshal(meta)
 			if err != nil {

cmd/genesis-writer/entities_user.go

@@ -125,7 +125,7 @@ func (w *Writer) writeUsers(ctx context.Context) error {
 		},
 		func(ctx context.Context, u sourceUser) error {
 			meta := userMetadata{
-				CreatedAt:           u.CreatedAt.UTC().Format(time.RFC3339),
+				CreatedAt:           u.CreatedAt.UTC().Format(time.RFC3339Nano),
 				Name:                deref(u.Name),
 				Handle:              deref(u.Handle),
 				Bio:                 deref(u.Bio),

cmd/genesis-writer/release_date_format_test.go

@@ -30,3 +30,66 @@ func TestReleaseDateIsEmittedInAnAcceptedLayout(t *testing.T) {
 		t.Errorf("nil release_date = %q, want empty so omitempty drops it", fmtReleaseDate(nil))
 	}
 }
+
+// RFC3339 has no fractional-second component, so formatting with it rounded
+// every sub-second release_date down to the whole second. The indexer accepts
+// RFC3339Nano, and a value with no fraction still formats identically, so
+// nothing about the layout above changes.
+func TestReleaseDateKeepsSubSecondPrecision(t *testing.T) {
+	rd := time.Date(2026, 2, 2, 15, 53, 12, 50585000, time.UTC)
+	got := fmtReleaseDate(&rd)
+
+	if got != "2026-02-02T15:53:12.050585Z" {
+		t.Errorf("fmtReleaseDate = %q, want %q -- microseconds were dropped", got, "2026-02-02T15:53:12.050585Z")
+	}
+
+	parsed, err := time.Parse(time.RFC3339Nano, got)
+	if err != nil {
+		t.Fatalf("indexer cannot parse %q: %v", got, err)
+	}
+	if !parsed.Equal(rd) {
+		t.Errorf("round-tripped to %v, want %v", parsed, rd)
+	}
+
+	// A whole-second value must still come out in the plain layout, so this
+	// change is invisible to the 99% of rows that carry no fraction.
+	whole := time.Date(2026, 9, 6, 22, 6, 0, 0, time.UTC)
+	if got := fmtReleaseDate(&whole); got != "2026-09-06T22:06:00Z" {
+		t.Errorf("whole-second release_date = %q, want %q", got, "2026-09-06T22:06:00Z")
+	}
+}
+
+// created_at went out through the same non-fractional layout, and it is not a
+// cosmetic field: the indexer replays each migrated row as of its created_at
+// (migrationBlockTime), and parity keys track_downloads on it. A full-snapshot
+// run truncated every one of the 78,032 track_downloads rows, plus ~2.9M
+// social rows, to the whole second.
+//
+// parseMigrationTimestamp tries RFC3339Nano before RFC3339, and Go's parser
+// accepts a fractional second against a layout that lacks one, so emitting the
+// longer form is safe for every reader.
+func TestEmittedCreatedAtKeepsSubSecondPrecision(t *testing.T) {
+	src := sourceTrack{
+		TrackID:   1,
+		OwnerID:   2,
+		CreatedAt: time.Date(2024, 12, 1, 12, 30, 13, 244308000, time.UTC),
+	}
+
+	got := buildTrackMetadata(src, nil).CreatedAt
+	if got != "2024-12-01T12:30:13.244308Z" {
+		t.Errorf("created_at = %q, want %q -- microseconds were dropped", got, "2024-12-01T12:30:13.244308Z")
+	}
+
+	parsed, err := time.Parse(time.RFC3339Nano, got)
+	if err != nil {
+		t.Fatalf("indexer cannot parse %q: %v", got, err)
+	}
+	if !parsed.Equal(src.CreatedAt) {
+		t.Errorf("round-tripped to %v, want %v", parsed, src.CreatedAt)
+	}
+
+	// The stricter RFC3339 layout used by event_create.go must still accept it.
+	if _, err := time.Parse(time.RFC3339, got); err != nil {
+		t.Errorf("plain RFC3339 parse rejected %q: %v", got, err)
+	}
+}

cmd/genesis-writer/timestamps_test.go

@@ -31,8 +31,11 @@ import (
 // worth guarding is a *new* emission site added later without .UTC(), and only
 // scanning the package catches that.
 func TestAllEmittedTimestampsAreUTC(t *testing.T) {
-	// A .Format(time.RFC3339) whose receiver does not end in .UTC().
-	unnormalized := regexp.MustCompile(`(\.UTC\(\))?\.Format\(time\.RFC3339\)`)
+	// A .Format(time.RFC3339Nano) whose receiver does not end in .UTC().
+	// RFC3339 is matched too so that reintroducing the non-fractional layout
+	// -- which silently rounded ~3M created_at values to the whole second --
+	// is still covered by the .UTC() half of this guard.
+	unnormalized := regexp.MustCompile(`(\.UTC\(\))?\.Format\(time\.RFC3339(Nano)?\)`)
 
 	entries, err := os.ReadDir(".")
 	if err != nil {