feat: add web layer (FastAPI + worker)

web/worker.py

@@ -0,0 +1,53 @@
+"""Worker process — polls task queue, executes run_pipeline()."""
+import json, sys, time, shutil
+from pathlib import Path
+
+sys.path.insert(0, str(Path(__file__).parent.parent))
+
+TASKS_DIR = Path("tasks")
+
+def main():
+    print("Worker started. Watching tasks/ ...")
+    while True:
+        for tf in sorted(TASKS_DIR.glob("*.json")):
+            try:
+                data = json.loads(tf.read_text())
+                if data.get("status") != "queued":
+                    continue
+
+                data["status"] = "running"
+                tf.write_text(json.dumps(data))
+
+                from config import Config
+                from orchestrator import run_pipeline
+
+                cfg = Config()
+                cfg.runner_mode = data.get("runner", "native")
+                if cfg.runner_mode == "spark" and not shutil.which("spark-submit"):
+                    data["status"] = "blocked"
+                    data["result"] = "spark-submit not installed"
+                    tf.write_text(json.dumps(data))
+                    continue
+
+                vr = run_pipeline(cfg, data["copybook"], data["cobol_src"],
+                                  data["java_src"], data["mapping"])
+
+                data["status"] = "done"
+                data["result"] = {
+                    "program": vr.program, "status": vr.status,
+                    "matched": vr.fields_matched, "mismatched": vr.fields_mismatched,
+                    "duration": vr.duration_s, "runner": vr.runner,
+                }
+                tf.write_text(json.dumps(data))
+
+            except Exception as e:
+                data = json.loads(tf.read_text()) if tf.exists() else {}
+                data["status"] = "error"
+                data["result"] = str(e)[:500]
+                tf.write_text(json.dumps(data))
+
+        time.sleep(2)
+
+
+if __name__ == "__main__":
+    main()