Custom workspace dropdown + Launch-Unreal button

Replace the ugly native <select> on the connect screen with a themed
custom dropdown (Select component). Add a Launch-Unreal button that appears
when the chosen working folder contains a .uproject: backend find_uproject
resolves the scope to disk and searches it (and one level down); the button
opens the project via the opener plugin. Bundled the UE icon (currentColor,
so white-on-dark / black-on-light per theme). New strings translated.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src-tauri/src/lib.rs

@@ -610,6 +610,54 @@ async fn open_in_explorer(state: State<'_, AppState>, target: String) -> Result<
     Ok(())
 }
 
+/// Look for an Unreal `.uproject` inside the working-folder scope (resolved to a
+/// local dir via `p4 where`). Checks the folder itself and one level of subdirs.
+/// Returns the local path of the first match, or "" if the scope isn't a UE project.
+#[tauri::command]
+async fn find_uproject(state: State<'_, AppState>, scope: String) -> Result<String, String> {
+    if scope.is_empty() {
+        return Ok(String::new());
+    }
+    let conn = current(&state)?;
+    let spec = format!("{}/...", scope.trim_end_matches(['/', '.']));
+    let dir = match run_json(&conn, &["where", &spec])?
+        .into_iter()
+        .next()
+        .and_then(|v| v.get("path").and_then(|p| p.as_str()).map(String::from))
+    {
+        Some(p) => p.trim_end_matches(['.', '/', '\\']).to_string(),
+        None => return Ok(String::new()),
+    };
+    let is_uproject = |p: &std::path::Path| {
+        p.extension().map_or(false, |x| x.eq_ignore_ascii_case("uproject"))
+    };
+    // the scope folder itself
+    if let Ok(entries) = std::fs::read_dir(&dir) {
+        let mut subdirs = Vec::new();
+        for e in entries.flatten() {
+            let p = e.path();
+            if is_uproject(&p) {
+                return Ok(p.to_string_lossy().to_string());
+            }
+            if p.is_dir() {
+                subdirs.push(p);
+            }
+        }
+        // one level down
+        for sd in subdirs {
+            if let Ok(inner) = std::fs::read_dir(&sd) {
+                for e in inner.flatten() {
+                    let p = e.path();
+                    if is_uproject(&p) {
+                        return Ok(p.to_string_lossy().to_string());
+                    }
+                }
+            }
+        }
+    }
+    Ok(String::new())
+}
+
 /// Files and metadata of a submitted changelist (History detail).
 #[tauri::command]
 async fn p4_describe(state: State<'_, AppState>, change: String) -> Result<Value, String> {
@@ -702,6 +750,7 @@ pub fn run() {
             p4_scan,
             p4_undo_change,
             open_in_explorer,
+            find_uproject,
             p4_describe,
             read_file,
             read_depot,