fix(memory): add coalesce defaults for activation_value and related node properties

- Add coalesce fallbacks for importance_score, activation_value, and
access_count in statement, entity, weak entity, strong entity, and
memory summary MERGE queries to prevent null values on new nodes
- Set activation_value default to coalesce(importance_score, 0.5) for
consistency with the forgetting/activation scoring logic
- Suppress Neo4j UNRECOGNIZED property key notifications in driver init
since missing keys like last_access_time and activation_value are
expected for newly created nodes

api/app/repositories/neo4j/cypher_queries.py

@@ -42,6 +42,9 @@ SET s += {
     last_access_time: statement.last_access_time,
     access_count: statement.access_count
 }
+SET s.importance_score = coalesce(s.importance_score, 0.5),
+    s.activation_value = coalesce(s.activation_value, s.importance_score, 0.5),
+    s.access_count = coalesce(s.access_count, 0)
 RETURN s.id AS uuid
 """
 
@@ -120,7 +123,7 @@ SET e.name = CASE WHEN entity.name IS NOT NULL AND entity.name <> '' THEN entity
         END
     END,
     e.importance_score = CASE WHEN entity.importance_score IS NOT NULL THEN entity.importance_score ELSE coalesce(e.importance_score, 0.5) END,
-    e.activation_value = CASE WHEN entity.activation_value IS NOT NULL THEN entity.activation_value ELSE e.activation_value END,
+    e.activation_value = CASE WHEN entity.activation_value IS NOT NULL THEN entity.activation_value ELSE coalesce(e.activation_value, e.importance_score, 0.5) END,
     e.access_history = CASE WHEN entity.access_history IS NOT NULL THEN entity.access_history ELSE coalesce(e.access_history, []) END,
     e.last_access_time = CASE WHEN entity.last_access_time IS NOT NULL THEN entity.last_access_time ELSE e.last_access_time END,
     e.access_count = CASE WHEN entity.access_count IS NOT NULL THEN entity.access_count ELSE coalesce(e.access_count, 0) END,
@@ -165,6 +168,7 @@ SET e += {
 }
 // Independent weak flag，仅标记弱关系，不再维护 relations 聚合字段
 SET e.is_weak = true
+SET e.activation_value = coalesce(e.activation_value, 0.5)
 RETURN e.id AS id
 """
 
@@ -175,10 +179,12 @@ MERGE (s:ExtractedEntity {id: item.source_id, run_id: item.run_id})
 SET s += {name: item.subject, end_user_id: item.end_user_id, run_id: item.run_id}
 // Independent strong flag
 SET s.is_strong = true
+SET s.activation_value = coalesce(s.activation_value, 0.5)
 MERGE (o:ExtractedEntity {id: item.target_id, run_id: item.run_id})
 SET o += {name: item.object, end_user_id: item.end_user_id, run_id: item.run_id}
 // Independent strong flag
 SET o.is_strong = true
+SET o.activation_value = coalesce(o.activation_value, 0.5)
 """
 
 
@@ -739,7 +745,7 @@ SET m += {
     summary_embedding: summary.summary_embedding,
     config_id: summary.config_id,
     importance_score: CASE WHEN summary.importance_score IS NOT NULL THEN summary.importance_score ELSE coalesce(m.importance_score, 0.5) END,
-    activation_value: CASE WHEN summary.activation_value IS NOT NULL THEN summary.activation_value ELSE m.activation_value END,
+    activation_value: CASE WHEN summary.activation_value IS NOT NULL THEN summary.activation_value ELSE coalesce(m.activation_value, m.importance_score, 0.5) END,
     access_history: CASE WHEN summary.access_history IS NOT NULL THEN summary.access_history ELSE coalesce(m.access_history, []) END,
     last_access_time: CASE WHEN summary.last_access_time IS NOT NULL THEN summary.last_access_time ELSE m.last_access_time END,
     access_count: CASE WHEN summary.access_count IS NOT NULL THEN summary.access_count ELSE coalesce(m.access_count, 0) END