Release v3.8.31 (#4377)

Release v3.8.31 — see CHANGELOG.md [3.8.31] for full notes and contributors.

Merged over known non-blocking reds (all correctness gates green): Integration Tests (2/2) is env/flaky (polls a real upstream batch that did not complete in the poll window); SonarQube/SonarCloud is the advisory server-side new-code quality gate. Unit (8 shards), Coverage, Node 22/24/26, Lint, PR Test Policy, Quality Ratchet, Docs-Strict, Quality-Extended and all 4 CodeQL analyses are green.

src/shared/utils/codexConfig.ts

@@ -0,0 +1,30 @@
+/**
+ * Helpers for generating/maintaining the Codex CLI `config.toml`.
+ */
+
+interface ParsedCodexToml {
+  _root: Record<string, unknown>;
+  _sections: Record<string, Record<string, unknown>>;
+}
+
+/**
+ * Migrate the deprecated Codex `[features].codex_hooks` flag to `[features].hooks`.
+ *
+ * Codex renamed the feature flag; recent Codex CLI versions ignore the old key and
+ * print a deprecation notice. When OmniRoute rewrites an existing `config.toml` it
+ * should carry the user's intent forward by renaming the key (preserving its value)
+ * and dropping the deprecated one. A no-op when `[features]` or `codex_hooks` is
+ * absent, and it never clobbers an already-present `hooks` value. (#1327)
+ *
+ * Operates in place on the route's parsed-TOML shape (`{ _root, _sections }`).
+ */
+export function migrateCodexFeatureFlags(parsed: ParsedCodexToml): ParsedCodexToml {
+  const features = parsed?._sections?.features;
+  if (!features || typeof features !== "object") return parsed;
+  if (!Object.prototype.hasOwnProperty.call(features, "codex_hooks")) return parsed;
+  if (!Object.prototype.hasOwnProperty.call(features, "hooks")) {
+    features.hooks = features.codex_hooks;
+  }
+  delete features.codex_hooks;
+  return parsed;
+}