Fix dangerous pkill, circular import, and dedup _res_suffix

- Scope pkill to 'pdal pipeline' (avoids killing unrelated PDAL jobs)
- Inline _strip_lidar_ext in dtm.py to remove circular import from pipeline
- _res_suffix_str now delegates to LidarArchaeoPipeline._res_suffix

lidar_pipeline/index.py

@@ -161,10 +161,9 @@ def _strip_res_suffix(dirname):
 
 
 def _res_suffix_str(resolution):
-    """Suffixe de nommage d'une résolution (miroir de pipeline._res_suffix)."""
-    if resolution == 0.5:
-        return ''
-    return '_r' + f'{resolution}'.replace('.', 'p')
+    """Suffixe de nommage d'une résolution (délègue à pipeline._res_suffix)."""
+    from .pipeline import LidarArchaeoPipeline
+    return LidarArchaeoPipeline._res_suffix(resolution)
 
 
 def scan_tiles(vis_dir):