Upgrade PDAL to 2.10 via conda-forge, add COPC v1.1 support

- Dockerfile: install PDAL 2.10.1 from conda-forge (was 2.3 from apt)
  Ubuntu 22.04's PDAL 2.3 cannot read COPC v1.1 files from IGN LiDAR HD
- dtm.py: add _read_with_pdal() fallback for COPC files that laspy can't read
- dtm.py: validate_laz() now tries PDAL when laspy fails
- dtm.py: create_dtm_fast() and detect_ground_method() use PDAL fallback
- ign.py: auto-retry at lower zoom on 404 errors
- pipeline.py: check DTM resolution mismatch and regenerate if needed
- pipeline.py: propagate actual DTM resolution to visualizations
- pipeline.py: add --init to docker run for proper Ctrl+C signal handling
- Remove RRIM and Multi-Hillshade RGB visualizations

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

Dockerfile

@@ -3,17 +3,21 @@ FROM nvidia/cuda:12.4.0-devel-ubuntu22.04
 ENV DEBIAN_FRONTEND=noninteractive
 ENV TZ=Europe/Paris
 
-# Install PDAL and system packages
+# Install system packages + Miniforge for PDAL >= 2.5 (Ubuntu 22.04 ships PDAL 2.3 which can't read COPC v1.1)
 RUN apt-get update && apt-get install -y --no-install-recommends \
-    pdal \
-    liblaszip8 \
     gdal-bin \
     python3-gdal \
     python3-pip \
     python3-dev \
     build-essential \
     wget \
-    && rm -rf /var/lib/apt/lists/*
+    && rm -rf /var/lib/apt/lists/* \
+    && wget -q https://github.com/conda-forge/miniforge/releases/latest/download/Miniforge3-Linux-x86_64.sh -O /tmp/miniforge.sh \
+    && bash /tmp/miniforge.sh -b -p /opt/conda \
+    && rm /tmp/miniforge.sh \
+    && /opt/conda/bin/conda install -y -c conda-forge pdal \
+    && ln -sf /opt/conda/bin/pdal /usr/local/bin/pdal \
+    && /opt/conda/bin/conda clean -afy
 
 WORKDIR /app