fix: audit fixes — power timeout, timing mitigation, release profile, GREETD_SOCK cache (v0.7.1)

- Add 30s timeout with SIGKILL to power actions (adapted from moonset)
- Add 500ms minimum login response time against timing enumeration
- Cache GREETD_SOCK in GreeterState at startup
- Add [profile.release] with LTO, codegen-units=1, strip
- Add compressed="true" to GResource CSS/SVG entries
- Add SYNC comments to duplicated blur/background functions
- Add nix dependency for signal handling in power timeout

Cargo.lock

@@ -59,6 +59,12 @@ version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
 
+[[package]]
+name = "cfg_aliases"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "613afe47fcd5fac7ccf1db93babcb082c5994d996f20b8b159f2ad1658eb5724"
+
 [[package]]
 name = "equivalent"
 version = "1.0.2"
@@ -569,7 +575,7 @@ dependencies = [
 
 [[package]]
 name = "moongreet"
-version = "0.7.0"
+version = "0.7.1"
 dependencies = [
  "gdk-pixbuf",
  "gdk4",
@@ -580,6 +586,7 @@ dependencies = [
  "gtk4",
  "gtk4-layer-shell",
  "log",
+ "nix",
  "serde",
  "serde_json",
  "systemd-journal-logger",
@@ -588,6 +595,18 @@ dependencies = [
  "zeroize",
 ]
 
+[[package]]
+name = "nix"
+version = "0.29.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "71e2746dc3a24dd78b3cfcb7be93368c6de9963d30f43a6a73998a9cf4b17b46"
+dependencies = [
+ "bitflags",
+ "cfg-if",
+ "cfg_aliases",
+ "libc",
+]
+
 [[package]]
 name = "once_cell"
 version = "1.21.4"