Add wall-clock timeout to parallel worker pool

Prevents indefinite hang if a worker gets stuck (deadlocked PDAL,
I/O stall). 2-hour safety net for the entire batch; remaining
futures are cancelled on timeout.

lidar_pipeline/pipeline.py

@@ -587,8 +587,14 @@ class LidarArchaeoPipeline:
                     for file_idx, laz_file in enumerate(files)
                 }
                 done = 0
+                t_deadline = time.time() + 7200
                 try:
                     for future in as_completed(future_to_file):
+                        if time.time() > t_deadline:
+                            logger.error("Délai dépassé (2h) — annulation des workers restants")
+                            for f in future_to_file:
+                                f.cancel()
+                            break
                         laz_file = future_to_file[future]
                         done += 1
                         try: