refactor: use echo to write manifest on flatpak

src-tauri/capabilities/default.json

@@ -24,7 +24,6 @@
     "sql:allow-execute",
     "fs:allow-app-write",
     "fs:allow-app-write-recursive",
-    "fs:allow-write-text-file",
     "updater:default",
     "process:default",
     "clipboard-manager:allow-read-text",

src-tauri/capabilities/shell.json

@@ -69,6 +69,11 @@
             "name": "cp",
             "cmd": "cp",
             "args": true
+        },
+        {
+            "name": "echo",
+            "cmd": "echo",
+            "args": true
         }
       ]
     },