fix: remove doubled -alpha-alpha version suffix

CARGO_PKG_VERSION already contains -alpha from Cargo.toml, so the
format!("{}-alpha", ...) was producing 1.2.0-alpha-alpha. Use the
Cargo version directly.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

core/archipelago/src/data_model.rs

@@ -244,7 +244,7 @@ impl DataModel {
         Self {
             server_info: ServerInfo {
                 id: uuid::Uuid::new_v4().to_string(),
-                version: format!("{}-alpha", env!("CARGO_PKG_VERSION")),
+                version: env!("CARGO_PKG_VERSION").to_string(),
                 name: Some("Archipelago".to_string()),
                 pubkey: String::new(),
                 status_info: StatusInfo {