Fix crashes in Postgres session adapter

packages/session/src/adapters/postgres.ts

···
   user_id: string;
   handle: string | null;
   is_authenticated: boolean;
-  data: string | null;
-  created_at: Date;
-  expires_at: Date;
-  last_accessed_at: Date;
+  data: Record<string, unknown> | null;
+  created_at: number;
+  expires_at: number;
+  last_accessed_at: number;
 }
 
 export class PostgresAdapter implements SessionAdapter {
···
           data.userId,
           data.handle || null,
           data.isAuthenticated,
-          data.data ? JSON.stringify(data.data) : null,
+          data.data || null,
           data.createdAt,
           data.expiresAt,
           data.lastAccessedAt,
···
     updates: Partial<SessionData>
   ): Promise<boolean> {
     const setParts: string[] = [];
-    const values: (string | number | boolean | null)[] = [];
+    const values: (string | number | boolean | null | Record<string, unknown>)[] = [];
     let paramIndex = 1;
 
     if (updates.userId !== undefined) {
···
 
     if (updates.data !== undefined) {
       setParts.push(`data = $${paramIndex++}`);
-      values.push(updates.data ? JSON.stringify(updates.data) : null);
+      values.push(updates.data || null);
     }
 
     if (updates.expiresAt !== undefined) {
···
       userId: row.user_id,
       handle: row.handle || undefined,
       isAuthenticated: row.is_authenticated,
-      data: row.data ? JSON.parse(row.data) : undefined,
-      createdAt: row.created_at.getTime(),
-      expiresAt: row.expires_at.getTime(),
-      lastAccessedAt: row.last_accessed_at.getTime(),
+      data: row.data || undefined,
+      createdAt: row.created_at,
+      expiresAt: row.expires_at,
+      lastAccessedAt: row.last_accessed_at,
     };
   }