Release v69

Replaced the empty string "" with "Select Tier"

Kept all other functionality the same

Release v68

Removed user_id=st.session_state.user_id from CodeRefactor() initiali…

Release v67

Removed user_id argument from CodeAnalyzer() initialization

Slightly reorganized the order of session state initialization
Kept the user_id initialization at the top

V2.0

Ran black src/ to reformat all Python files in the src directory

Verified with black --check src/ that all files are now formatted