feat(cli): let a build name its own version

A nightly printed the same 19.0.0 as the release it followed, so a bug
report could not say which one it came from. SOULSEEK_RS_VERSION at
compile time replaces the crate version in --version, the TUI and the
daemon status.

soulseek-rs/src/ui/downloads.rs

@@ -1,3 +1,4 @@
+use crate::cli::VERSION;
 use crate::models::DownloadEntry;
 use crate::ui::{
     BYTES_PER_MB, accent_style, dimmed_style, error_style,
@@ -14,8 +15,6 @@ use ratatui::{
 use soulseek_rs::DownloadStatus;
 use std::fmt::Write as _;
 
-const VERSION: &str = env!("CARGO_PKG_VERSION");
-
 /// Bytes transferred, bytes expected and combined speed across the downloads
 /// that are actually running — or `None` when none are, so the caller can hide
 /// the progress readout entirely.