chore(deps): add regex, hex, percent-encoding for v1.1.0 stdlib

Workspace deps for the seven Rhai utility modules that follow in this
PR. `rand`, `base64`, `uuid`, `chrono`, `serde_json` are already in
the workspace and reused as-is — only the genuinely new ones land here.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Cargo.toml

@@ -74,6 +74,12 @@ sha2 = "0.10"
 base64 = "0.22"
 data-encoding = "2.6"
 
+# Stdlib utility crates (v1.1.0 stdlib PR — registered into the
+# Rhai engine as the regex::/random::/etc. namespaces)
+regex = "1"
+hex = "0.4"
+percent-encoding = "2"
+
 [workspace.lints.rust]
 unsafe_code = "forbid"