Add debug mode agent status logging

[ulivz]

Description

Agent Server needs structured logging in debug mode to display complete agent runtime status through special log formats.

Expected Behavior

When logLevel: DEBUG is enabled, output structured logs containing:

• Current execution status and SessionId
• User task description
• Current operation/phase
• Final execution result

Current Behavior

Missing structured agent runtime status logs for debugging and monitoring.

Implementation Context

Relevant code locations:

• multimodal/tarko/agent-server/src/core/AgentSession.ts - Session lifecycle and query execution
• multimodal/tarko/agent-server/src/server.ts - Server configuration with isDebug flag
• multimodal/tarko/agent-server/src/api/controllers/sessions.ts - Session management endpoints

// Current debug detection in server.ts
this.isDebug = appConfig.logLevel === LogLevel.DEBUG;

// Session execution in AgentSession.ts
async runQuery(query: string | ChatCompletionContentPart[]): Promise<AgentQueryResponse> {
  try {
    this.server.setRunningSession(this.id);
    // Add structured debug logging here
    const result = await this.agent.run(runOptions);
    return { success: true, result };
  } finally {
    this.server.clearRunningSession(this.id);
  }
}

Acceptance Criteria

• Add structured debug logs for session lifecycle events
• Log current execution status with SessionId
• Include user task description in logs
• Track current operation/phase during execution
• Log final execution results
• Use consistent log format for easy parsing
• Only activate when logLevel: DEBUG is set

Related

• [Feature]: Agent Server exclusive mode support #1148 (Agent Server exclusive mode support)