feat(FN-2617): merge fusion/fn-2617 (auto-resolved)

- test(FN-2617): stabilize workflow remediation timeout under full suite
- test(FN-2617): complete Step 5 — add openclaw runtime resolution coverage
- feat(FN-2617): complete Step 4 — route step sessions through runtime resolution
- fix(FN-2617): thread runtimeHint through merger rebase push flow
- feat(FN-2617): complete Step 3 — wire runtimeHint across engine subsystems
- feat(FN-2617): complete Step 2 — thread runtimeHint in executor paths
- feat(FN-2617): complete Step 1 — add runtimeHint extraction helper

packages/engine/src/agent-session-helpers.ts

@@ -42,6 +42,24 @@ export interface ResolvedSessionResult {
   wasConfigured: boolean;
 }
 
+/**
+ * Extract runtime hint from untyped runtimeConfig payload.
+ *
+ * @param runtimeConfig - Agent/task runtime configuration
+ * @returns normalized runtime hint or undefined when missing/invalid
+ */
+export function extractRuntimeHint(
+  runtimeConfig: Record<string, unknown> | undefined,
+): string | undefined {
+  const hint = runtimeConfig?.runtimeHint;
+  if (typeof hint !== "string") {
+    return undefined;
+  }
+
+  const normalizedHint = hint.trim();
+  return normalizedHint.length > 0 ? normalizedHint : undefined;
+}
+
 /**
  * Create an agent session using runtime resolution.
  *