feat: rendering library v1 (#15778)

The goal will be to replace askama

codex-rs/Cargo.toml

@@ -70,6 +70,7 @@ members = [
     "utils/path-utils",
     "utils/fuzzy-match",
     "utils/stream-parser",
+    "utils/template",
     "codex-client",
     "codex-api",
     "state",
@@ -166,6 +167,7 @@ codex-utils-rustls-provider = { path = "utils/rustls-provider" }
 codex-utils-sandbox-summary = { path = "utils/sandbox-summary" }
 codex-utils-sleep-inhibitor = { path = "utils/sleep-inhibitor" }
 codex-utils-stream-parser = { path = "utils/stream-parser" }
+codex-utils-template = { path = "utils/template" }
 codex-utils-string = { path = "utils/string" }
 codex-windows-sandbox = { path = "windows-sandbox-rs" }
 core_test_support = { path = "core/tests/common" }
@@ -383,7 +385,7 @@ ignored = [
     "icu_provider",
     "openssl-sys",
     "codex-utils-readiness",
-    "codex-secrets",
+    "codex-utils-template",
     "codex-v8-poc",
 ]