Inject a thank you after each message

Key features

• Only injected at the step containing direct user input (turn's first model request), falling at the bottom of the payload
• Added role-playing style reply guidance
• There is no need to restart after modifying settings.yaml: DSH's dsh-settings-file enables file hot reloading (chokidar, 100ms anti-shake) by default, and changes will automatically take effect within 1-2 seconds.
• Adapt to the thinking chain overwriting mode of the warehouse
• Only look at the length of the most recent assistant reply