refactor: use workflows-ai under the hood

[grabbou]

Fixes #64 #52 #49 #42

This is internal rewrite to offer much better execution flow and potentially advanced workflows in the future.

• Removed custom error handling in actions. We will now use an agent/wrapper to handle errors
• Simplified tools return format and also, cleaned-up readme
• Removed rslib in favor of tsup and removed custom patch-package for Vercel AI SDK (we no longer use that feature)
• Removed entire CLI logic that is now handled by the ai-flows package (entire logic is one big flow). We will further improve it by adding additional blocks for error handling later