Add update and check commands with UTC package timestamps

Cargo.lock

@@ -382,7 +382,7 @@ checksum = "807800ff3288b621186fe0a8f3392c4652068257302709c24efd918c3dffcdc2"
 
 [[package]]
 name = "depot"
-version = "0.12.2"
+version = "0.13.0"
 dependencies = [
  "anyhow",
  "ar",
@@ -410,6 +410,7 @@ dependencies = [
  "tar",
  "tempfile",
  "thiserror 2.0.18",
+ "time",
  "toml",
  "url",
  "walkdir",
@@ -2040,9 +2041,9 @@ dependencies = [
 
 [[package]]
 name = "tempfile"
-version = "3.25.0"
+version = "3.26.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0136791f7c95b1f6dd99f9cc786b91bb81c3800b639b3478e561ddb7be95e5f1"
+checksum = "82a72c767771b47409d2345987fda8628641887d5466101319899796367354a0"
 dependencies = [
  "fastrand",
  "getrandom 0.4.1",
@@ -2107,11 +2108,13 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "743bd48c283afc0388f9b8827b976905fb217ad9e647fae3a379a9283c4def2c"
 dependencies = [
  "deranged",
+ "itoa",
  "js-sys",
  "num-conv",
  "powerfmt",
  "serde_core",
  "time-core",
+ "time-macros",
 ]
 
 [[package]]
@@ -2120,6 +2123,16 @@ version = "0.1.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7694e1cfe791f8d31026952abf09c69ca6f6fa4e1a1229e18988f06a04a12dca"
 
+[[package]]
+name = "time-macros"
+version = "0.2.27"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2e70e4c5a0e0a8a4823ad65dfe1a6930e4f4d756dcd9dd7939022b5e8c501215"
+dependencies = [
+ "num-conv",
+ "time-core",
+]
+
 [[package]]
 name = "tinystr"
 version = "0.8.2"