fix: build-windows.bat — forcer réinstall pip deps + retirer plugins.shell.scope

- build-windows.bat: supprimer python-embed/ à chaque build (plus de skip si python.exe existe)
  Sans ça, uvicorn manquait car installé une seule fois puis jamais recopié
- tauri.conf.json: retirer plugins.shell.scope — déprécié en Tauri v2, géré par capabilities

desktop/build-windows.bat

@@ -18,7 +18,6 @@ echo ✅ Rust + Tauri OK
 
 REM ── 2. Préparer Python 3.11 embed ─────────────────────────────
 echo [2/5] Preparing Python embed...
-if not exist "python-embed\python.exe" (
 echo 📥 Downloading Python 3.11 embed...
 if exist "python-embed" rmdir /s /q "python-embed"
 curl -L -o python-embed.zip "https://www.python.org/ftp/python/3.11.9/python-3.11.9-embed-amd64.zip"
@@ -30,7 +29,6 @@ if not exist "python-embed\python.exe" (
 
 REM Install dependencies
 python-embed\python.exe -m pip install --no-cache-dir -r ..\backend\requirements.txt
-)
 echo ✅ Python embed ready
 
 REM ── 3. Build Tauri ────────────────────────────────────────────

desktop/tauri.conf.json

@@ -76,14 +76,7 @@
   },
   "plugins": {
     "shell": {
-      "open": true,
+      "open": true
-      "scope": [
-        {
-          "name": "python-backend",
-          "cmd": "./python-embed/python",
-          "args": ["-m", "uvicorn", "backend.main:app", "--host", "127.0.0.1", "--port", "17890"]
-        }
-      ]
     }
   }
 }