feat: Add experiments framework and novelty-driven agent loop

- Add complete experiments directory with pilot study infrastructure
  - 5 experimental conditions (direct, expert-only, attribute-only, full-pipeline, random-perspective)
  - Human assessment tool with React frontend and FastAPI backend
  - AUT flexibility analysis with jump signal detection
  - Result visualization and metrics computation

- Add novelty-driven agent loop module (experiments/novelty_loop/)
  - NoveltyDrivenTaskAgent with expert perspective perturbation
  - Three termination strategies: breakthrough, exhaust, coverage
  - Interactive CLI demo with colored output
  - Embedding-based novelty scoring

- Add DDC knowledge domain classification data (en/zh)
- Add CLAUDE.md project documentation
- Update research report with experiment findings

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

experiments/assessment/start.sh

@@ -0,0 +1,101 @@
+#!/bin/bash
+
+# Human Assessment Web Interface Start Script
+# This script starts both the backend API and frontend dev server
+
+set -e
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+cd "$SCRIPT_DIR"
+
+# Colors for output
+RED='\033[0;31m'
+GREEN='\033[0;32m'
+YELLOW='\033[1;33m'
+NC='\033[0m' # No Color
+
+echo -e "${GREEN}================================${NC}"
+echo -e "${GREEN}Creative Idea Assessment System${NC}"
+echo -e "${GREEN}================================${NC}"
+echo
+
+# Find Python with FastAPI (use project venv or system)
+VENV_PYTHON="$SCRIPT_DIR/../../backend/venv/bin/python"
+if [ -x "$VENV_PYTHON" ]; then
+    PYTHON_CMD="$VENV_PYTHON"
+    UVICORN_CMD="$SCRIPT_DIR/../../backend/venv/bin/uvicorn"
+else
+    PYTHON_CMD="python3"
+    UVICORN_CMD="uvicorn"
+fi
+
+# Check if assessment data exists
+if [ ! -f "data/assessment_items.json" ]; then
+    echo -e "${YELLOW}Assessment data not found. Running prepare_data.py...${NC}"
+    $PYTHON_CMD prepare_data.py
+    echo
+fi
+
+# Check if node_modules exist in frontend
+if [ ! -d "frontend/node_modules" ]; then
+    echo -e "${YELLOW}Installing frontend dependencies...${NC}"
+    cd frontend
+    npm install
+    cd ..
+    echo
+fi
+
+# Function to cleanup background processes on exit
+cleanup() {
+    echo
+    echo -e "${YELLOW}Shutting down...${NC}"
+    kill $BACKEND_PID 2>/dev/null || true
+    kill $FRONTEND_PID 2>/dev/null || true
+    exit 0
+}
+
+trap cleanup SIGINT SIGTERM
+
+# Start backend
+echo -e "${GREEN}Starting backend API on port 8002...${NC}"
+cd backend
+$UVICORN_CMD app:app --host 0.0.0.0 --port 8002 --reload &
+BACKEND_PID=$!
+cd ..
+
+# Wait for backend to start
+echo "Waiting for backend to initialize..."
+sleep 2
+
+# Check if backend is running
+if ! curl -s http://localhost:8002/api/health > /dev/null 2>&1; then
+    echo -e "${RED}Backend failed to start. Check for errors above.${NC}"
+    kill $BACKEND_PID 2>/dev/null || true
+    exit 1
+fi
+echo -e "${GREEN}Backend is running.${NC}"
+echo
+
+# Start frontend
+echo -e "${GREEN}Starting frontend on port 5174...${NC}"
+cd frontend
+npm run dev &
+FRONTEND_PID=$!
+cd ..
+
+# Wait for frontend to start
+sleep 3
+
+echo
+echo -e "${GREEN}================================${NC}"
+echo -e "${GREEN}Assessment system is running!${NC}"
+echo -e "${GREEN}================================${NC}"
+echo
+echo -e "Backend API:  ${YELLOW}http://localhost:8002${NC}"
+echo -e "Frontend UI:  ${YELLOW}http://localhost:5174${NC}"
+echo
+echo -e "Press Ctrl+C to stop all services"
+echo
+
+# Wait for any process to exit
+wait