fix: prevent native modules from being bundled for client-side code

[sh1ftred]

Summary

This PR fixes the Module not found error that occurred when running npm run dev, caused by better-sqlite3 being bundled for client-side code.

Changes

Root Cause

better-sqlite3 is a native Node.js module that requires fs, which does not exist in browser environments.

Fixes Applied

1. next.config.ts

   • Added better-sqlite3 to serverExternalPackages to exclude from bundling
   • Added webpack null-loader rules for native Node.js modules (fs, path, crypto)
   • Added fallback configuration for Node.js modules

2. sdk/storage/drivers/sqlite.ts

   • Changed require("better-sqlite3") to dynamic await import("better-sqlite3")
   • Added lazy initialization pattern for async database loading
   • Added webpackIgnore comment for bun:sqlite import

3. sdk/storage/usageTracking/sqlite.ts

   • Applied the same dynamic import pattern

4. Type System Updates

   • Added "lazyrefund" to RoutstrClientMode type
   • Added "lazyrefund" to RouteRequestOptions.mode

5. Script Updates

   • Updated check-balance.ts, refund-all.ts, set-client-ids.ts to fix type compatibility issues
   • Updated to use new storage API (getCachedReceiveTokens instead of getCachedTokenDistribution)

Testing

• npm run build succeeds
• npm run dev starts successfully without errors