### What problem does this PR solve?
refactor: Moves the LLM factory initialization logic to the `dao`
package.
Removes the `init_data` package and integrates the LLM factory
initialization functionality into the `dao` package.
Adds a `utility` package to provide general utility functions.
Updates `server_main.go` to use the new initialization path.
### Type of change
- [x] Bug Fix (non-breaking change which fixes an issue)
Co-authored-by: Jin Hai <haijin.chn@gmail.com>
