Darken the screen in frozen capture mode

Frozen mode showed the still image at full brightness until a selection
existed, unlike live mode's dark veil. It now draws the same 35% veil over
everything and re-draws the selected area from the snapshot, keeping the
selection bright. The hint text matches the mode.

💘 Generated with Crush

Assisted-by: Crush:deepseek-v4-flash-0731

build-app.sh

@@ -108,9 +108,9 @@ cat > "$APP/Contents/Info.plist" <<'PLIST'
     <key>CFBundleIconFile</key>
     <string>Icon</string>
     <key>CFBundleShortVersionString</key>
-    <string>1.10.0</string>
+    <string>1.10.1</string>
     <key>CFBundleVersion</key>
-    <string>100</string>
+    <string>101</string>
     <key>LSUIElement</key>
     <true/>
     <key>NSHighResolutionCapable</key>