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

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "moonset"
-version = "0.8.0"
+version = "0.8.1"
 edition = "2024"
 description = "Wayland session power menu with GTK4 and Layer Shell"
 license = "MIT"
@@ -22,5 +22,10 @@ systemd-journal-logger = "2.2"
 [dev-dependencies]
 tempfile = "3"
 
+[profile.release]
+lto = "thin"
+codegen-units = 1
+strip = true
+
 [build-dependencies]
 glib-build-tools = "0.22"