fix(studio): Cmd+; opens Settings (Cmd+, is reserved by macOS) (v0.12.1)

Operator reported Cmd+, doing nothing. macOS reserves Cmd+,
for the native app-Preferences menu item which Flutter Desktop
doesn't wire up — the keystroke is captured by the OS before
the Shortcuts widget sees it.

Adds Cmd+; as the working alternative; keeps Cmd+, registered
too so a future Flutter version (or a native-menu setup) can
light it up. Tooltip on the sidebar gear icon now reads
"Settings (⌘;)" so the discoverable affordance also tells you
the shortcut.

Signed-off-by: flemming-it <stefan.a.flemming@googlemail.com>

pubspec.yaml

@@ -1,7 +1,7 @@
 name: fai_studio
 description: "F∆I Studio — desktop GUI for the F∆I hub"
 publish_to: 'none'
-version: 0.12.0
+version: 0.12.1
 
 environment:
   sdk: ^3.11.0-200.1.beta