feat: modules batch paths + masquage manuel + templates de masque

- gui_batch_paths.py : listing documents + construction chemins de sortie batch
- manual_masking.py : masquage manuel piloté par templates YAML
- config/mask_templates/ : template FC19

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

config/mask_templates/FC19_template.yml

@@ -0,0 +1,18 @@
+version: 1
+name: FC19_template
+page_size:
+  width: 595.0
+  height: 842.0
+masks:
+- page: 0
+  x0: 123.2
+  y0: 25.6
+  x1: 485.6
+  y1: 66.4
+  label: MASK
+- page: 0
+  x0: 205.6
+  y0: 351.2
+  x1: 341.6
+  y1: 367.2
+  label: MASK