Fix: CsI(Tl) non-linear response correction + detector calibration overhaul

Root cause of Am-241 misidentification: the Radiacode 103's CsI(Tl) crystal
shifts low-energy peaks upward (59.5 keV → 71.6 keV for Am-241) due to
non-proportional scintillation response. The model was trained on theoretical
peak positions and couldn't match the shifted real peaks.

Changes:
- Add inverse CsI(Tl) non-linear correction to inference pipeline
  (radiacode_monitor.py, web/config.py, test_detection.py)
  E_apparent = E_true * (1 + 0.37 * exp(-E_true/100))
  Corrects channel mapping so peaks appear at theoretical energies
- Fix energy calibration: DetectorConfig now uses E = 0.33 + 2.97*ch
  with 1023 channels, matching the real detector (was energy_min=20,
  skip_first_channel=True, different channel width)
- Add K-escape peaks for CsI(Tl) iodine X-ray escape (E - 28.5 keV)
- Add asymmetric peak shapes for low-energy tails (< 200 keV)
- Add log1p normalization in dataset and inference (replaces max-norm)
- Add background-subtracted training mode (subtract_background flag)
- Add low-signal augmentation (0.01-5 Bq activities, 30-300s durations)
- Update docker-compose.yml: batch_size=32, duration=30-300s,
  CSI_NONLINEAR_ALPHA/BETA env vars for detect and web
- Web dashboard: apply CsI correction to displayed spectra
- Various UI fixes (Chart.js width, zoom/pan, isotope lines)

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

train/entrypoint.sh

@@ -5,11 +5,11 @@ DATA_DIR="${DATA_DIR:-/data/synthetic}"
 MODEL_DIR="${MODEL_DIR:-/models}"
 NUM_SAMPLES="${NUM_SAMPLES:-50000}"
 EPOCHS="${EPOCHS:-100}"
-BATCH_SIZE="${BATCH_SIZE:-64}"
+BATCH_SIZE="${BATCH_SIZE:-32}"
 LEARNING_RATE="${LEARNING_RATE:-0.001}"
 DETECTOR="${DETECTOR:-radiacode_103}"
-MIN_DURATION="${MIN_DURATION:-43200}"
-MAX_DURATION="${MAX_DURATION:-86400}"
+MIN_DURATION="${MIN_DURATION:-30}"
+MAX_DURATION="${MAX_DURATION:-300}"
 SEED="${SEED:-42}"
 MEASURED_BACKGROUND_PATH="${MEASURED_BACKGROUND_PATH:-}"
 
@@ -20,7 +20,7 @@ echo "  Data dir    : $DATA_DIR"
 echo "  Model dir   : $MODEL_DIR"
 echo "  Samples     : $NUM_SAMPLES"
 echo "  Detector    : $DETECTOR"
-echo "  Duration     : $MIN_DURATION-$MAX_DURATION s"
+echo "  Duration    : $MIN_DURATION-$MAX_DURATION s"
 echo "  Epochs      : $EPOCHS"
 echo "  Batch size  : $BATCH_SIZE"
 echo "  Learning rate: $LEARNING_RATE"