#519 [API/Memory] Workflow graph generation - unbounded recursion

**File:** api/blueprints/v1/workflows.py:1283-1307, 1488-1526 **Problem:** Deeply nested workflows (parallel within loops within parallel) cause exponential dict growth. No recursion depth limit. Malicious/malformed workflows can trigger OOM. **Fix:** ```python MAX_TASK_COUNT = 10000 MAX_RECURSION_DEPTH = 50 def _extract_all_tasks(tasks_dict, parent_prefix="", depth=0): if depth > MAX_RECURSION_DEPTH: raise ValueError("Workflow nesting too deep") if len(all_tasks) > MAX_TASK_COUNT: raise ValueError("Too many tasks in workflow") ``` **Impact:** OOM on malicious workflow submissions.