migrate: replace NextAuth.js with Better Auth

- Install better-auth and @better-auth/drizzle-adapter
- Create src/lib/auth.ts with Better Auth configuration using bcrypt
- Update database schema: change auth table IDs from uuid to text
- Update route handler from /api/auth/[...nextauth] to /api/auth/[...all]
- Update tRPC context and middleware for Better Auth session handling
- Update client components to use Better Auth APIs (signIn, signOut)
- Update seed script with text-based IDs and correct account schema
- Fix type errors in wizard components (robotId, optional chaining)
- Fix API paths: api.robots.initialize -> api.robots.plugins.initialize
- Update auth router to use text IDs for Better Auth compatibility

Note: Auth tables were reset - users will need to re-register.

src/hooks/useWebSocket.ts

@@ -2,7 +2,7 @@
 
 /* eslint-disable react-hooks/exhaustive-deps */
 
-import { useSession } from "next-auth/react";
+import { useSession } from "~/lib/auth-client";
 import { useCallback, useEffect, useRef, useState } from "react";
 
 export type TrialStatus =