poc-agent: read context_groups from config instead of hardcoded list

- Remove MEMORY_FILES constant from identity.rs
- Add ContextGroup struct for deserializing from config
- Load context_groups from ~/.config/poc-agent/config.json5
- Check ~/.config/poc-agent/ first for identity files, then project/global
- Debug screen now shows what's actually configured

This eliminates the hardcoded duplication and makes the debug output
match what's in the config file.

scripts/provision-mistralrs.sh

@@ -0,0 +1,50 @@
+#!/bin/bash
+# provision-mistralrs.sh — Set up mistral.rs on a RunPod GPU instance
+#
+# Alternative to vLLM for inference. Pure Rust, more debuggable,
+# OpenAI-compatible API. Testing whether it fixes the IncompleteMessage
+# errors we're seeing with vLLM on large payloads.
+#
+# Usage: ssh into your RunPod instance and run this script.
+# Runs on port 8001 to coexist with vLLM on 8000.
+
+set -euo pipefail
+
+MODEL="${MODEL:-Qwen/Qwen3.5-27B}"
+PORT="${PORT:-8001}"
+
+echo "=== mistral.rs provisioning ==="
+echo "Model: $MODEL"
+echo "Port:  $PORT"
+echo ""
+
+# --- Verify GPU ---
+echo "GPU status:"
+nvidia-smi --query-gpu=name,memory.total,memory.free --format=csv,noheader
+echo ""
+
+# --- Install mistral.rs ---
+echo "Installing mistral.rs..."
+curl --proto '=https' --tlsv1.2 -sSf \
+    https://raw.githubusercontent.com/EricLBuehler/mistral.rs/master/install.sh | sh
+
+# --- Use persistent storage for model cache ---
+export HF_HOME="${HF_HOME:-/workspace/huggingface}"
+mkdir -p "$HF_HOME"
+
+# --- Run hardware tune first ---
+echo "Running hardware benchmark..."
+mistralrs tune
+
+# --- Start server ---
+echo ""
+echo "Starting mistral.rs server on port $PORT..."
+echo "API: http://0.0.0.0:$PORT/v1"
+echo "UI:  http://0.0.0.0:$PORT/ui"
+echo ""
+
+# Run in foreground (use screen/tmux to background)
+mistralrs serve \
+    --ui \
+    --port "$PORT" \
+    -m "$MODEL"