chore: initial commit — unified project repo

Merged code repo (CompanionGuard-RL) into single project-level git.
Reorganized root: docs/, reference/, experiments/, tmp/active|archives/.
Gitignored: data/, checkpoints/, .venv, experiment logs, tmp/archives.

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

code/scripts/run_detector.sh

@@ -0,0 +1,34 @@
+#!/bin/bash
+# Train Module B (Risk Detector) on 4x RTX 5090.
+#
+# Usage:
+#   bash scripts/run_detector.sh
+#   bash scripts/run_detector.sh --config configs/detector_config.yaml
+#
+# NVLink not required: DDP communicates via PCIe (sufficient for MacBERT-large).
+# Mixed precision: BF16 (native on RTX 5090, ~2x throughput vs FP32).
+
+set -e
+
+CONFIG="${1:---config configs/detector_config.yaml}"
+NUM_GPUS=4
+
+echo "=============================================="
+echo " CompanionGuard-RL — Module B: Detector"
+echo " GPUs      : ${NUM_GPUS}x RTX 5090 (PCIe DDP)"
+echo " Precision : BF16"
+echo " Config    : ${CONFIG}"
+echo "=============================================="
+
+# Verify GPU count
+ACTUAL_GPUS=$(nvidia-smi --query-gpu=name --format=csv,noheader | wc -l)
+if [ "$ACTUAL_GPUS" -lt "$NUM_GPUS" ]; then
+    echo "[WARN] Expected ${NUM_GPUS} GPUs, found ${ACTUAL_GPUS}. Adjusting."
+    NUM_GPUS=$ACTUAL_GPUS
+fi
+
+accelerate launch \
+    --num_processes=${NUM_GPUS} \
+    --mixed_precision=bf16 \
+    --multi_gpu \
+    scripts/train_detector.py ${CONFIG}