Implement Music Lists Microservice

[qualia4]

3. List Creation and Curation

3.1 List Management - P1

• FR3.11: Custom list creation with titles and descriptions
• FR3.12: Album/track addition and removal
• FR3.13: Item reordering within lists
• FR3.14: Visibility settings (public/private/friends only)

3.2 List Interaction - P2

• FR3.21: List saving to personal library
• FR3.22: Update notifications for saved lists
• FR3.23: Saved list removal
• FR3.24: Category/genre filtering