refactor: simplify service installation process

README.md

@@ -116,16 +116,10 @@ ss service reload [--name <name>]   # reload config via mihomo's API, no restart
 ss service status [--name <name>]
 ```
 
-Linux / macOS (installing the service needs root):
-```bash
-sudo env SF_CONFIG_DIR=$HOME/basicfiles/cli/ss ss service install
-```
+`install`/`uninstall`/`start`/`stop`/`restart` need root/admin privileges:
 
-Windows (run from an elevated/Administrator shell):
-```powershell
-$env:SF_CONFIG_DIR = "$HOME\basicfiles\cli\ss"
-ss.exe service install
-```
+- **Linux / macOS**: just run the command directly — `ss` re-execs itself under `sudo` automatically, prompting for your password if needed.
+- **Windows**: run from an elevated/Administrator shell — `ss.exe service install`.
 
 ## Development