refactor(memory): enhance extraction ontology and add assistant pruning graph support

- Expand entity type ontology with detailed definitions, examples, and notes
  (merged types: 地点设施, 物品设备, 产品服务, 软件平台, 角色职业, 知识能力, 偏好习惯目标, 称呼别名, 智能体)
- Add relation ontology taxonomy with 15 predicate categories and usage rules
- Strengthen reference resolution rules: resolve pronouns before extraction,
  skip unresolvable references entirely
- Add guidelines to avoid extracting abstract propositions, emotions, and
  low-value entities (effort/reward/success patterns)
- Add 7 new extraction examples covering edge cases
- Add AssistantOriginal/AssistantPruned node models and graph persistence
  (PRUNED_TO and BELONGS_TO_DIALOG edges, Neo4j indexes and constraints)
- Add graph_build_step.py for building graph nodes/edges from DialogData
- Update write_pipeline.py to pass assistant pruning nodes/edges to graph saver
- Update data_pruning.py with related preprocessing changes

api/app/repositories/neo4j/create_indexes.py

@@ -46,6 +46,12 @@ async def create_fulltext_indexes():
             OPTIONS { indexConfig: { `fulltext.analyzer`: 'cjk' } }
         """)
 
+        # 创建 AssistantPruned 剪枝文本全文索引
+        await connector.execute_query("""
+            CREATE FULLTEXT INDEX assistantPrunedFulltext IF NOT EXISTS FOR (p:AssistantPruned) ON EACH [p.text]
+            OPTIONS { indexConfig: { `fulltext.analyzer`: 'cjk' } }
+        """)
+
     finally:
         await connector.close()
 
@@ -135,6 +141,17 @@ async def create_vector_indexes():
               `vector.similarity_function`: 'cosine'
             }}
         """)
+
+        # AssistantPruned text embedding index (optional, for semantic search on pruned hints)
+        await connector.execute_query("""
+            CREATE VECTOR INDEX assistant_pruned_embedding_index IF NOT EXISTS
+            FOR (p:AssistantPruned)
+            ON p.text_embedding
+            OPTIONS {indexConfig: {
+              `vector.dimensions`: 1024,
+              `vector.similarity_function`: 'cosine'
+            }}
+        """)
     finally:
         await connector.close()
 
@@ -179,6 +196,22 @@ async def create_unique_constraints():
             """
         )
 
+        # AssistantOriginal.id unique
+        await connector.execute_query(
+            """
+            CREATE CONSTRAINT assistant_original_id_unique IF NOT EXISTS
+            FOR (o:AssistantOriginal) REQUIRE o.id IS UNIQUE
+            """
+        )
+
+        # AssistantPruned.id unique
+        await connector.execute_query(
+            """
+            CREATE CONSTRAINT assistant_pruned_id_unique IF NOT EXISTS
+            FOR (p:AssistantPruned) REQUIRE p.id IS UNIQUE
+            """
+        )
+
     finally:
         await connector.close()