test(domain): pin audit serde contracts; loosen time version; note null caveat

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Cargo.lock

@@ -361,6 +361,16 @@ dependencies = [
  "zeroize",
 ]
 
+[[package]]
+name = "deranged"
+version = "0.5.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7cd812cc2bc1d69d4764bd80df88b4317eaef9e773c75226407d9bc0876b211c"
+dependencies = [
+ "powerfmt",
+ "serde_core",
+]
+
 [[package]]
 name = "digest"
 version = "0.10.7"
@@ -389,6 +399,8 @@ name = "domain"
 version = "0.0.0"
 dependencies = [
  "serde",
+ "serde_json",
+ "time",
  "uuid",
 ]
 
@@ -1067,6 +1079,12 @@ dependencies = [
  "zeroize",
 ]
 
+[[package]]
+name = "num-conv"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "51d515d32fb182ee37cda2ccdcb92950d6a3c2893aa280e540671c2cd0f3b1d9"
+
 [[package]]
 name = "num-integer"
 version = "0.1.46"
@@ -1201,6 +1219,12 @@ dependencies = [
  "zerovec",
 ]
 
+[[package]]
+name = "powerfmt"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "439ee305def115ba05938db6eb1644ff94165c5ab5e9420d1c1bcedbba909391"
+
 [[package]]
 name = "ppv-lite86"
 version = "0.2.21"
@@ -2013,6 +2037,36 @@ dependencies = [
  "cfg-if",
 ]
 
+[[package]]
+name = "time"
+version = "0.3.45"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f9e442fc33d7fdb45aa9bfeb312c095964abdf596f7567261062b2a7107aaabd"
+dependencies = [
+ "deranged",
+ "num-conv",
+ "powerfmt",
+ "serde_core",
+ "time-core",
+ "time-macros",
+]
+
+[[package]]
+name = "time-core"
+version = "0.1.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8b36ee98fd31ec7426d599183e8fe26932a8dc1fb76ddb6214d05493377d34ca"
+
+[[package]]
+name = "time-macros"
+version = "0.2.25"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "71e552d1249bf61ac2a52db88179fd0673def1e1ad8243a00d9ec9ed71fee3dd"
+dependencies = [
+ "num-conv",
+ "time-core",
+]
+
 [[package]]
 name = "tinystr"
 version = "0.8.3"