Document the upgrade steps and always print them after a release

Readers and future sessions need one obvious place that says how to move
an installed app to the latest version, and the release flow now requires
surfacing those commands in every release report.

💘 Generated with Crush

Assisted-by: Crush:deepseek-v4.1-flash

README.md

@@ -44,14 +44,27 @@ brew install --cask simpletopbar
 The tap is hosted on Gitea, so the full URL is required. Homebrew may print an
 "Unsupported tap" warning — it's harmless.
 
+## Upgrade
+
+```bash
+brew update
+brew upgrade --cask simpletopbar
+```
+
+If Gatekeeper still blocks the app after upgrading (it is not notarized yet):
+
+```bash
+xattr -dr com.apple.quarantine /Applications/SimpleTopBar.app
+```
+
 ## Build from source
 
 ```bash
 swift build                 # debug build
 swift run SimpleTopBar      # run from terminal (app appears in the menu bar)
 swift run SimpleTopBar --self-test   # headless check of the dropdown logic
-./build-app.sh 0.1.0        # release build + SimpleTopBar.app bundle + icon + codesign
-./release.sh 0.1.0          # build-app.sh + dist/SimpleTopBar.zip + sha256
+./build-app.sh 0.2.0        # release build + SimpleTopBar.app bundle + icon + codesign
+./release.sh 0.2.0          # build-app.sh + dist/SimpleTopBar.zip + sha256
 ```
 
 ## Around the Background dropdown