Project Harmonia

Getting it to compile wasn't too hard, thanks to the migration guide and deprecation warnings.

I took the time to rewrite my logic using new features like observers, fallible params, required components, picking, etc. The rewrite is massive: 98 files changed, 5197 insertions, 6303 deletions. And that's excluding Cargo.lock - it's all code.

I really like the changes. They made the code much clearer. Next, I plan some work on my crates.