feat: enhance agent orchestration, knowledge flow and UI refinements

backend/app/models/agent.py

@@ -1,4 +1,4 @@
-from sqlalchemy import Column, String, Text, Boolean, ForeignKey, Integer
+from sqlalchemy import Column, String, Text, Boolean, ForeignKey, Integer, JSON
 from sqlalchemy.orm import relationship
 from app.models.base import BaseModel
 
@@ -7,9 +7,10 @@ class Agent(BaseModel):
     __tablename__ = "agents"
 
     name = Column(String(100), nullable=False)
-    role = Column(String(100), nullable=False)  # master, planner, executor, librarian, analyst
+    role = Column(String(100), nullable=False)  # master, schedule_planner, executor, librarian, analyst
     description = Column(Text, nullable=True)
     system_prompt = Column(Text, nullable=False)
+    selected_skill_ids = Column(JSON, default=list, nullable=False)
     is_active = Column(Boolean, default=True)
     is_default = Column(Boolean, default=False)