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/frontend/src/hooks/useRatings.ts

@@ -0,0 +1,133 @@
+/**
+ * Hook for managing rating submission.
+ */
+
+import { useState, useCallback } from 'react';
+import type { RatingState, DimensionKey } from '../types';
+import * as api from '../services/api';
+
+interface UseRatingsOptions {
+  raterId: string | null;
+  queryId: string | null;
+  ideaId: string | null;
+  onSuccess?: () => void;
+}
+
+export function useRatings({ raterId, queryId, ideaId, onSuccess }: UseRatingsOptions) {
+  const [ratings, setRatings] = useState<RatingState>({
+    originality: null,
+    elaboration: null,
+    coherence: null,
+    usefulness: null,
+  });
+  const [submitting, setSubmitting] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+
+  // Set a single rating
+  const setRating = useCallback((dimension: DimensionKey, value: number | null) => {
+    setRatings((prev) => ({ ...prev, [dimension]: value }));
+  }, []);
+
+  // Reset all ratings
+  const resetRatings = useCallback(() => {
+    setRatings({
+      originality: null,
+      elaboration: null,
+      coherence: null,
+      usefulness: null,
+    });
+    setError(null);
+  }, []);
+
+  // Check if all ratings are set
+  const isComplete = useCallback(() => {
+    return (
+      ratings.originality !== null &&
+      ratings.elaboration !== null &&
+      ratings.coherence !== null &&
+      ratings.usefulness !== null
+    );
+  }, [ratings]);
+
+  // Submit rating
+  const submit = useCallback(async () => {
+    if (!raterId || !queryId || !ideaId) {
+      setError('Missing required information');
+      return false;
+    }
+
+    if (!isComplete()) {
+      setError('Please rate all dimensions');
+      return false;
+    }
+
+    setSubmitting(true);
+    setError(null);
+
+    try {
+      await api.submitRating({
+        rater_id: raterId,
+        idea_id: ideaId,
+        query_id: queryId,
+        originality: ratings.originality,
+        elaboration: ratings.elaboration,
+        coherence: ratings.coherence,
+        usefulness: ratings.usefulness,
+        skipped: false,
+      });
+
+      resetRatings();
+      onSuccess?.();
+      return true;
+    } catch (err) {
+      setError(err instanceof Error ? err.message : 'Failed to submit rating');
+      return false;
+    } finally {
+      setSubmitting(false);
+    }
+  }, [raterId, queryId, ideaId, ratings, isComplete, resetRatings, onSuccess]);
+
+  // Skip idea
+  const skip = useCallback(async () => {
+    if (!raterId || !queryId || !ideaId) {
+      setError('Missing required information');
+      return false;
+    }
+
+    setSubmitting(true);
+    setError(null);
+
+    try {
+      await api.submitRating({
+        rater_id: raterId,
+        idea_id: ideaId,
+        query_id: queryId,
+        originality: null,
+        elaboration: null,
+        coherence: null,
+        usefulness: null,
+        skipped: true,
+      });
+
+      resetRatings();
+      onSuccess?.();
+      return true;
+    } catch (err) {
+      setError(err instanceof Error ? err.message : 'Failed to skip idea');
+      return false;
+    } finally {
+      setSubmitting(false);
+    }
+  }, [raterId, queryId, ideaId, resetRatings, onSuccess]);
+
+  return {
+    ratings,
+    setRating,
+    resetRatings,
+    isComplete,
+    submit,
+    skip,
+    submitting,
+    error,
+  };
+}