Replace tsup with bunchee for all packages

[0x80]

Fixes #43

Summary

This PR replaces the tsup bundler with bunchee across all packages in the monorepo, improving build performance and simplifying the build pipeline.

Changes Made

All Packages

• Core Package: Replaced tsup with bunchee in build script
• API Service: Replaced tsup with bunchee in build script
• Functions Service: Replaced tsup with bunchee in build script
• Removed tsup.config.ts files from all packages
• Updated build commands to use bunchee --sourcemap --runtime node --target es2022

Dependencies

• Added bunchee@^6.6.0 to all packages
• Removed tsup@^8.3.6 from all packages
• Cleaned up duplicate module field in package.json files

Build Configuration

• Build commands now use bunchee's native Node.js runtime targeting
• Maintained sourcemap generation for debugging
• Preserved ES2022 target compatibility

Build Pipeline Simplification

• No more tsc declaration emission: bunchee handles TypeScript declaration file generation natively
• No more tsc-alias dependency: bunchee automatically resolves TypeScript path aliases during bundling
• Cleaner build process: Single command now handles bundling, declarations, and alias resolution

Benefits

• Faster builds: bunchee is generally faster than tsup for Node.js targets
• Smaller bundles: More efficient bundling for server-side code
• Simplified config: Removed need for separate tsup configuration files
• Better tree-shaking: bunchee provides improved dead code elimination
• Streamlined pipeline: Eliminated need for post-build TypeScript compilation and alias processing
• Native TypeScript support: Better integration with TypeScript ecosystem