fix: audit fixes — release profile, GResource compression, lock stderr, sync markers (v0.8.1)

- Add [profile.release] with LTO, codegen-units=1, strip
- Add compressed="true" to GResource CSS/SVG entries
- Inherit moonlock stderr instead of /dev/null (errors visible in journal)
- Add SYNC comments to duplicated blur/background functions

resources/resources.gresource.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <gresources>
   <gresource prefix="/dev/moonarch/moonset">
-    <file>style.css</file>
-    <file>default-avatar.svg</file>
+    <file compressed="true">style.css</file>
+    <file compressed="true">default-avatar.svg</file>
   </gresource>
 </gresources>