feat(isce2): harden managed production flow

- add one-time base DEM preparation utility and prepared-first DEM resolution

- support geocode resume/full-geocode and guard large unprepared DEMs

- repair missing completion files during in-place ISCE2 publish rebuild

- add ISCE2 stabilization update log

.env.example

@@ -85,6 +85,7 @@ ORBIT_POOL_LANDSAR=
 # -----------------------------------------------------------------------------
 # DEM / 其他数据
 # -----------------------------------------------------------------------------
+# Raw D-InSAR DEM source for SARscape/ENVI. Keep the base path without the .wgs84 suffix here.
 IDL_DINSAR_DEM_BASE_FILE=D:\SRTM30m\SRTMDEM_RSP_SARscape
 SRTM_DEM_DIR=D:\SRTM30m
 GF3_GEO_DEM_PATH=D:\DEM\gf3_dem.jp2
@@ -138,6 +139,7 @@ ISCE2_PYTHON=/home/administrator/miniconda3/envs/insar_wsl_v1/bin/python
 ISCE2_PROFILE=lt1_stripmap
 ISCE2_STRIPMAP_APP=/home/administrator/miniconda3/envs/insar_wsl_v1/lib/python3.11/site-packages/isce/applications/stripmapApp.py
 ISCE2_PIPELINE_SCRIPT=
+# ISCE2 should point to the prepared WGS84 DEM after the one-time conversion.
 ISCE2_DEM_PATH=D:\SRTM30m\SRTMDEM_RSP_SARscape.wgs84
 ISCE2_WORK_ROOT=D:\Code\Insar_management_system_v2\backend\runtime\isce2_work
 ISCE2_OUTPUT_ROOT=D:\production_results\dinsar
@@ -159,6 +161,7 @@ PYINT_OUTPUT_ROOT=D:\production_results\dinsar
 PYINT_DEM_ROOT=D:\Code\Insar_management_system_v2\backend\runtime\pyint_dem
 PYINT_DEM_MODE=local_fabdem
 PYINT_FABDEM_ROOT=
+# When PYINT_DEM_MODE=prepared_file, point this to the same prepared WGS84 DEM.
 PYINT_PREPARED_DEM_PATH=
 PYINT_OPENTOPO_DEM_TYPE=SRTMGL1
 PYINT_DEM_STRICT=true