Preload audio using once_cell and correct typo

Add once_cell 1.21.4 and a Lazy‑initialized HashMap to store OGG bytes.

Replace file reads with in‑memory Cursor decoding, fix the
SoundrackParts enum typo, and derive Hash traits for it.

Cargo.lock

@@ -1204,9 +1204,9 @@ dependencies = [
 
 [[package]]
 name = "once_cell"
-version = "1.21.3"
+version = "1.21.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "42f5e15c9953c5e4ccceeb2e7382a716482c34515315f7b03532b8b4e8393d2d"
+checksum = "9f7c3e4beb33f85d45ae3e3a1792185706c8e16d043238c593331cc7cd313b50"
 
 [[package]]
 name = "once_cell_polyfill"
@@ -2237,6 +2237,7 @@ version = "0.1.0"
 dependencies = [
  "clap",
  "log",
+ "once_cell",
  "ratatui",
  "rodio",
  "simplelog",