The library sort setting used `size` for largest-first sorting while the
ascending option used `sizeAsc`. That made the pair asymmetric and left the
current settings model carrying a legacy-looking key.
Rename the current descending key to `sizeDesc` in the type, menu, and sort
logic. Stored `size` values are normalized to `sizeDesc` on read, so existing
users keep the same largest-first behavior while new writes use the explicit
key.
Test Plan:
- deno task build
- RUSTC_WRAPPER= CARGO_BUILD_RUSTC_WRAPPER= just build
- git diff --check
Refs: local review feedback
ddidderr
ebeee2d90a
