feat(parser): add Shelley (exe.dev) agent support

frontend/src/lib/components/settings/AgentDirSettings.svelte

@@ -24,6 +24,7 @@
     piebald: "Piebald",
     antigravity: "Antigravity",
     "antigravity-cli": "Antigravity CLI",
+    shelley: "Shelley",
   };
 </script>
 

internal/db/messages.go

@@ -1175,11 +1175,10 @@ func (db *DB) MessageTokenFingerprint(sessionID string) (string, error) {
 
 // MessageContentHashFingerprint returns an exact ordered fingerprint
 // of per-message body content: ordinal, the stored content_length
-// column, and a SHA-256 over the sanitized content. The parse-diff
-// comparator uses it instead of the aggregate
-// MessageContentFingerprint (sum/max/min of content_length, kept for
-// the PG push fast-path), which cannot see equal-length body rewrites
-// or per-message length changes whose aggregates collide.
+// column, and a SHA-256 over the sanitized content. Parse-diff and PG
+// push use it alongside the aggregate MessageContentFingerprint
+// (sum/max/min of content_length), which cannot see equal-length body
+// rewrites or per-message length changes whose aggregates collide.
 func (db *DB) MessageContentHashFingerprint(sessionID string) (string, error) {
 	rows, err := db.getReader().Query(
 		`SELECT ordinal, content, content_length
@@ -1221,6 +1220,20 @@ func (db *DB) MessageContentHashFingerprint(sessionID string) (string, error) {
 // (selectMessageCols coalesces the same way); without it a single
 // imported NULL row would error here and abort the whole parse-diff run.
 func (db *DB) MessageRoleTimeFingerprint(sessionID string) (string, error) {
+	return db.MessageRoleTimeFingerprintWithTimestampNormalizer(
+		sessionID, nil,
+	)
+}
+
+// MessageRoleTimeFingerprintWithTimestampNormalizer returns the same
+// fingerprint as MessageRoleTimeFingerprint after applying normalizeTimestamp
+// to each timestamp value. It lets callers compare against stores that preserve
+// a different timestamp representation while keeping the query and field
+// ordering identical to the raw parse-diff fingerprint.
+func (db *DB) MessageRoleTimeFingerprintWithTimestampNormalizer(
+	sessionID string,
+	normalizeTimestamp func(string) string,
+) (string, error) {
 	rows, err := db.getReader().Query(
 		`SELECT ordinal, role, COALESCE(timestamp, '')
 		 FROM messages
@@ -1241,6 +1254,9 @@ func (db *DB) MessageRoleTimeFingerprint(sessionID string) (string, error) {
 			return "", err
 		}
 		role = SanitizeUTF8(role)
+		if normalizeTimestamp != nil {
+			timestamp = normalizeTimestamp(timestamp)
+		}
 		fmt.Fprintf(&b, "%d|%d:%s|%d:%s;",
 			ordinal, len(role), role, len(timestamp), timestamp)
 	}
@@ -1253,7 +1269,8 @@ func (db *DB) MessageRoleTimeFingerprint(sessionID string) (string, error) {
 // has_tool_use, and a SHA-256 over the sanitized thinking_text. The
 // parse-diff comparator uses it as a tier-1 fast path so a parser change
 // confined to these columns still triggers the tier-2 row comparison.
-// Not used by the PG push fast-path.
+// PG push uses it with a PostgreSQL-side twin to avoid skipping
+// metadata-only rewrites.
 func (db *DB) MessageFlagsFingerprint(sessionID string) (string, error) {
 	rows, err := db.getReader().Query(
 		`SELECT ordinal, is_system, has_thinking, has_tool_use,

internal/db/sessions.go

@@ -1323,20 +1323,49 @@ func (db *DB) GetSessionMessageCount(
 	return count, true
 }
 
-// GetSessionVersion returns the message count and file mtime
-// for change detection in SSE watchers.
+// SessionVersionMarker returns a compact marker for one or more
+// version fields. Inputs are length-framed so adjacent fields cannot
+// collide by concatenation.
+func SessionVersionMarker(parts ...string) int64 {
+	const (
+		offset64 = uint64(14695981039346656037)
+		prime64  = uint64(1099511628211)
+	)
+	h := offset64
+	write := func(s string) {
+		for _, b := range []byte(s) {
+			h ^= uint64(b)
+			h *= prime64
+		}
+	}
+	for _, part := range parts {
+		write(fmt.Sprintf("%d:", len(part)))
+		write(part)
+	}
+	return int64(h)
+}
+
+// GetSessionVersion returns the message count and a compact version
+// marker for change detection in SSE watchers.
 func (db *DB) GetSessionVersion(
 	id string,
-) (count int, fileMtime int64, ok bool) {
+) (count int, version int64, ok bool) {
+	var fileMtime int64
+	var fileHash, localModifiedAt string
 	err := db.getReader().QueryRow(
-		"SELECT message_count, COALESCE(file_mtime, 0)"+
+		"SELECT message_count, COALESCE(file_mtime, 0),"+
+			" COALESCE(file_hash, ''), COALESCE(local_modified_at, '')"+
 			" FROM sessions WHERE id = ?",
 		id,
-	).Scan(&count, &fileMtime)
+	).Scan(&count, &fileMtime, &fileHash, &localModifiedAt)
 	if err != nil {
 		return 0, 0, false
 	}
-	return count, fileMtime, true
+	return count, SessionVersionMarker(
+		fmt.Sprintf("%d", fileMtime),
+		fileHash,
+		localModifiedAt,
+	), true
 }
 
 // IncrementalInfo holds the data needed for incremental
@@ -1517,6 +1546,25 @@ func (db *DB) GetFileInfoByPath(
 	return s.Int64, m.Int64, true
 }
 
+// GetFileHashByPath returns the stored file_hash for the session
+// matching file_path, preferring the most recently modified row.
+// The bool is false when no row exists or the column is NULL. Used
+// by the Shelley skip to compare a per-conversation content
+// fingerprint alongside file_mtime.
+func (db *DB) GetFileHashByPath(path string) (hash string, ok bool) {
+	var h sql.NullString
+	err := db.getReader().QueryRow(
+		"SELECT file_hash FROM sessions"+
+			" WHERE file_path = ?"+
+			" ORDER BY file_mtime DESC LIMIT 1",
+		path,
+	).Scan(&h)
+	if err != nil {
+		return "", false
+	}
+	return h.String, h.Valid
+}
+
 // GetDataVersionByPath returns the minimum data_version for
 // sessions matching a file_path. Returns 0 when no session
 // exists for the path.

internal/db/store.go

@@ -45,7 +45,7 @@ type Store interface {
 	SecretFindingSource(ctx context.Context, f SecretFinding) (string, bool, error)
 
 	// SSE change detection.
-	GetSessionVersion(id string) (count int, fileMtime int64, ok bool)
+	GetSessionVersion(id string) (count int, version int64, ok bool)
 
 	// Metadata.
 	GetStats(ctx context.Context, excludeOneShot, excludeAutomated bool) (Stats, error)

internal/duckdb/store.go

@@ -399,21 +399,31 @@ func (s *Store) GetChildSessions(ctx context.Context, parentID string) ([]db.Ses
 
 func (s *Store) GetSessionVersion(id string) (int, int64, bool) {
 	var count int
+	var fileMtime sql.NullInt64
+	var fileHash sql.NullString
 	var updated any
 	err := s.duck.QueryRow(
-		`SELECT message_count, COALESCE(local_modified_at, ended_at, started_at, created_at)
+		`SELECT message_count, file_mtime, file_hash,
+		        COALESCE(local_modified_at, ended_at, started_at, created_at)
 		 FROM sessions WHERE id = ?`,
 		id,
-	).Scan(&count, &updated)
+	).Scan(&count, &fileMtime, &fileHash, &updated)
 	if err != nil {
 		return 0, 0, false
 	}
-	formatted := formatDBTime(updated)
-	var h int64
-	for _, c := range formatted {
-		h = h*31 + int64(c)
+	fileMtimePart := ""
+	if fileMtime.Valid {
+		fileMtimePart = fmt.Sprintf("%d", fileMtime.Int64)
 	}
-	return count, h, true
+	fileHashPart := ""
+	if fileHash.Valid {
+		fileHashPart = fileHash.String
+	}
+	return count, db.SessionVersionMarker(
+		fileMtimePart,
+		fileHashPart,
+		formatDBTime(updated),
+	), true
 }
 
 func (s *Store) GetStats(ctx context.Context, excludeOneShot, excludeAutomated bool) (db.Stats, error) {