chore: C2 DELETE 204+body, C4 cached_tokens, C5 utcnow + LICENSE (T011)

agent_platform/db.py

@@ -8,7 +8,7 @@ import aiosqlite
 import json
 import uuid
 import secrets
-from datetime import datetime, timedelta
+from datetime import datetime, timedelta, timezone
 from pathlib import Path
 from config import settings
 
@@ -267,7 +267,7 @@ async def list_audit(db, agent_id=None, limit=100):
 
 async def create_session(db, user_id="default", ttl_hours=24):
     token = secrets.token_urlsafe(32)
-    expires = (datetime.utcnow() + timedelta(hours=ttl_hours)).isoformat()
+    expires = (datetime.now(timezone.utc).replace(tzinfo=None) + timedelta(hours=ttl_hours)).isoformat()
     await db.execute(
         "INSERT INTO sessions (token, user_id, expires_at) VALUES (?, ?, ?)",
         (token, user_id, expires)
@@ -284,6 +284,6 @@ async def validate_session(db, token):
         row = await cur.fetchone()
         if not row:
             return None
-        if row[1] and datetime.fromisoformat(row[1]) < datetime.utcnow():
+        if row[1] and datetime.fromisoformat(row[1]) < datetime.now(timezone.utc).replace(tzinfo=None):
             return None
         return row[0]