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/data/random_words.json

@@ -0,0 +1,28 @@
+{
+  "description": "Word pool for C5 random-perspective condition",
+  "version": "1.0",
+  "selection_criteria": [
+    "Concrete and evocative (easy to generate associations)",
+    "Diverse domains (no overlap with typical expert knowledge)",
+    "No obvious connection to test queries",
+    "Equal representation across conceptual categories"
+  ],
+  "categories": {
+    "nature": ["ocean", "mountain", "forest", "desert", "cave"],
+    "optics": ["microscope", "telescope", "kaleidoscope", "prism", "lens"],
+    "animals": ["butterfly", "elephant", "octopus", "eagle", "ant"],
+    "weather": ["sunrise", "thunderstorm", "rainbow", "fog", "aurora"],
+    "art": ["clockwork", "origami", "mosaic", "symphony", "ballet"],
+    "temporal": ["ancient", "futuristic", "organic", "crystalline", "liquid"],
+    "sensory": ["whisper", "explosion", "rhythm", "silence", "echo"]
+  },
+  "words": [
+    "ocean", "mountain", "forest", "desert", "cave",
+    "microscope", "telescope", "kaleidoscope", "prism", "lens",
+    "butterfly", "elephant", "octopus", "eagle", "ant",
+    "sunrise", "thunderstorm", "rainbow", "fog", "aurora",
+    "clockwork", "origami", "mosaic", "symphony", "ballet",
+    "ancient", "futuristic", "organic", "crystalline", "liquid",
+    "whisper", "explosion", "rhythm", "silence", "echo"
+  ]
+}