Document safe iPhone app updates

iphone_app/README.md

@@ -66,11 +66,25 @@ cp /var/mobile/IPhoneMCP/.manual_build/IPhoneMCP.app/Info.plist "$PKGROOT/Applic
 chmod 755 "$PKGROOT/Applications/IPhoneMCP.app/IPhoneMCP"
 chown -R root:wheel "$PKGROOT"
 dpkg-deb -b "$PKGROOT" "$DEB"
+killall IPhoneMCP 2>/dev/null || true
 dpkg -i "$DEB"
-uicache -p /Applications/IPhoneMCP.app
-uiopen com.reynafamily.iphonemcp
 ```
 
+For an update, launch **iPhone MCP** again from its Home Screen icon. Do not run
+`uiopen com.reynafamily.iphonemcp`: this jailbreak's `uiopen` command expects a
+URL, not an application bundle identifier.
+
+Only run the following after the first installation if the icon does not appear:
+
+```sh
+uicache -p /Applications/IPhoneMCP.app
+```
+
+Stop the app before running it and let `uicache` exit normally. Interrupting a
+refresh can leave the application database busy and make app launches appear to
+crash. If that happens, recover it over SSH with `killall -9 uicache`, then tap
+the app icon again.
+
 Verify listeners:
 
 ```sh