spec: add BEHAVIOR_SPEC and fix B-01~B-10 (resolved/decay/scoring)

- Add BEHAVIOR_SPEC.md as full system behaviour reference
- B-01: stop auto-archiving resolved buckets in update()
- B-03: keep activation_count as float in calculate_score
- B-04: initialise activation_count=0 on create
- B-05: time score coefficient 0.1 -> 0.02
- B-06: w_time default 2.5 -> 1.5
- B-07: content_weight default 3.0 -> 1.0
- B-08: refresh local meta after auto_resolve
- B-09: user-supplied valence/arousal takes priority over analyze()
- B-10: allow empty domain for feel buckets
- Refresh INTERNALS/README/dashboard accordingly

tests/test_scoring.py

@@ -1,3 +1,4 @@
+import pytest_asyncio
 # ============================================================
 # Test 1: Scoring Regression — pure local, no LLM needed
 # 测试 1：评分回归 —— 纯本地，不需要 LLM
@@ -22,7 +23,7 @@ from tests.dataset import DATASET
 # ============================================================
 # Fixtures: populate temp buckets from dataset
 # ============================================================
-@pytest.fixture
+@pytest_asyncio.fixture
 async def populated_env(test_config, bucket_mgr, decay_eng):
     """Create all dataset buckets in temp dir, return (bucket_mgr, decay_eng, bucket_ids)."""
     import frontmatter as fm