improvemets & fixes:

- added 'open with' handling to desktop shortcuts
- move logs button to app configuration
- fix sync progress disappearing after long hashing
- fix sync double file counter
- merge wine and proton prefix folders via symlink

src/ipc/games.js

@@ -107,21 +107,33 @@ function createGamesService({ getWindow, onGamesChanged }) {
     if (onGameExit) onGameExit(id)
   }
 
-  async function start(win, id) {
+  async function start(win, id, openFile) {
     const game = library.getGame(id)
     if (!game) return { ok: false, error: 'game-not-found' }
     prune()
-    if (running.has(id)) return { ok: false, error: 'already-running' }
     let wine
     try {
       wine = resolveWine(game)
     } catch {
       return { ok: false, error: 'wine-not-found' }
     }
+    if (running.has(id)) {
+      // Opening a document in an app that is already running is a HANDOFF,
+      // exactly like Windows: a second process receives the file and the app's
+      // own single-instance logic takes it over. It is not a tracked run -
+      // playtime, the tray and the kill switch belong to the first process.
+      if (!openFile) return { ok: false, error: 'already-running' }
+      try {
+        await runGame({ game, wine, systemWine: wine.type === 'system', openFile, handoff: true })
+        return { ok: true, pid: null, logFile: null }
+      } catch (err) {
+        return { ok: false, error: String((err && err.message) || err) }
+      }
+    }
     running.set(id, { pid: null, prefix: library.prefixNameForGame(game), wine: wine.id })
     startedAt.set(id, Date.now())
     try {
-      const res = await runGame({ game, wine, systemWine: wine.type === 'system', onExit: () => handleExit(id) })
+      const res = await runGame({ game, wine, systemWine: wine.type === 'system', onExit: () => handleExit(id), openFile })
       // stop was requested while the process was still starting: kill it and
       // leave nothing in the running set
       if (killRequests.has(id)) {