Adds OSC support cause why not

[DingosGotMyBaby]

Branch based of of my previous PR

[Lethalchip]

Thanks, the bucket-and-merge-per-tick approach is the right shape. Changes needed before merge:

1. Please drop the "Adds multi-platform support" commit (d42b54d). Linux support is being handled in feat: make pogly cli compatible with linux distros #4 with CI and release jobs; this copy conflicts with it, and the .or_else(|| asset_url(release, "pogly.exe")) fallback would install a Windows binary on Linux if the Linux asset were ever missing.
2. Remove the cross-tick last_sent_elements cache and the deadband in should_update_field. Two bugs: (a) changes of 1 unit are dropped and never re-sent, so transparency 1 -> 0 or 99 -> 100 never reaches the overlay and a fader can't land on its end value; (b) the cache never sees changes made in the editor, so after someone drags an element elsewhere, OSC sending the cached value is filtered as "no change". The per-tick merge in BucketedState already deduplicates bursts; sending every merged tick is correct.
3. CI is red: cargo fmt --check (23 hunks) and clippy with -D warnings (2x or_insert_with(Map::new) -> or_default(), 7x assert_eq!(x, true/false) -> assert!). The tests that assert the deadband behaviour need updating with item 2.
4. coerce_to_u32 accepts negative ints/floats and wraps (-1 as u32); please return an error instead.
5. README: note that --host 0.0.0.0 exposes unauthenticated control of the overlay to the network; keep the 127.0.0.1 default.

Since this is stacked on #1, it'll need a rebase once #1 lands.