Skip ground classification when DTM already exists

If the DTM .tif exists and --force is not set, skip both ground
classification and DTM generation entirely. Previously, the pipeline
would spend 3+ minutes reclassifying ground even when the DTM was
already present and would be reused anyway.

Also includes: SharedDEM cache, enhanced WebP cartouche (compass rose,
adaptive scale bar, enriched info bar), removed COG/viewer, UTF-8
fix for parallel workers, skip logic for DTM and PDF.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

lidar_pipeline/cli.py

@@ -23,6 +23,12 @@ def setup_logging(verbose=False, debug=False):
         verbose: If True, include timestamps and level names.
         debug:    If True, set level to DEBUG and add file:line info.
     """
+    # Ensure UTF-8 output for French messages (é, è, ê, etc.)
+    if hasattr(sys.stdout, 'reconfigure'):
+        sys.stdout.reconfigure(encoding='utf-8', errors='replace')
+    if hasattr(sys.stderr, 'reconfigure'):
+        sys.stderr.reconfigure(encoding='utf-8', errors='replace')
+
     if debug:
         level = logging.DEBUG
         fmt = "%(asctime)s.%(msecs)03d %(levelname)-5s [%(filename)s:%(lineno)d] %(message)s"
@@ -116,11 +122,6 @@ Exemples:
         action="store_true",
         help="Conserver les fichiers TIFF intermédiaires (sinon supprimés après conversion WebP)"
     )
-    parser.add_argument(
-        "--no-viewer",
-        action="store_true",
-        help="Ne pas générer le viewer web (COGs + HTML MapLibre)"
-    )
     parser.add_argument(
         "--ground-classification",
         choices=["auto", "smrf", "pmf", "csf"],
@@ -176,7 +177,6 @@ Exemples:
             ground_method=args.ground_classification,
             force_classify=args.force_classification,
             keep_tif=args.keep_tif,
-            no_viewer=args.no_viewer
         )
 
         # If --file is specified, process only matching files