Add RBAC: admin user management, audit log, runtime settings, delete PC

server/models.py

@@ -54,6 +54,7 @@ class AuditLog(Base):
 
     id = Column(Integer, primary_key=True, index=True)
     user_id = Column(Integer, ForeignKey("users.id", ondelete="SET NULL"), nullable=True)
+    username = Column(String, nullable=True)
     action = Column(String, nullable=False)
     details = Column(Text, nullable=True)
     timestamp = Column(DateTime(timezone=True), server_default=func.now())
@@ -71,3 +72,12 @@ class Notification(Base):
     sent_at = Column(DateTime(timezone=True), server_default=func.now())
     read_at = Column(DateTime(timezone=True), nullable=True)
 
+
+class Setting(Base):
+    __tablename__ = "settings"
+
+    id = Column(Integer, primary_key=True, index=True)
+    key = Column(String, unique=True, nullable=False, index=True)
+    value = Column(Text, nullable=True)
+    updated_at = Column(DateTime(timezone=True), server_default=func.now(), onupdate=func.now())
+