fix: Electron desktop app startup and add install script

- tryElectronApp() now finds the project directory via
  LAZY_UPDATE_MANAGER_DIR env, CWD, binary path, or $HOME
- Launches node_modules/.bin/electron directly instead of npm start
  (avoids recompiling the Go backend on every launch)
- Add install.sh with Electron fallback, desktop launcher, and
  prefer_electron config
- Desktop entry points to electron launcher for wofi support
- Update electron to v41.7.1

package-lock.json

@@ -9,7 +9,7 @@
       "version": "0.1.0",
       "license": "MIT",
       "devDependencies": {
-        "electron": "^41.5.0",
+        "electron": "^41.7.1",
         "electron-builder": "^26.0.0"
       }
     },
@@ -1747,9 +1747,9 @@
       }
     },
     "node_modules/electron": {
-      "version": "41.5.0",
-      "resolved": "https://registry.npmjs.org/electron/-/electron-41.5.0.tgz",
-      "integrity": "sha512-x9j9//PubUA4EjDtQbZhtk3prolandqCKgit0uCIqc1jb8FTskPbnJtxcDFB1aejczJcuERgjPixBUaMwoWyJg==",
+      "version": "41.7.1",
+      "resolved": "https://registry.npmjs.org/electron/-/electron-41.7.1.tgz",
+      "integrity": "sha512-pdRvNNP99Qfvs1lyIxo/sfIGAwJP0CrJFNCE3goFKc7/fV+kjK3EPxx5Nt6sLTkzqTyeRYylpwPUfpeGojiyyw==",
       "dev": true,
       "hasInstallScript": true,
       "license": "MIT",