fix: Reset token counters on new session for accurate usage display (#2099)

run_agent.py

@@ -1016,6 +1016,43 @@ class AIAgent:
                 print(f"📊 Context limit: {self.context_compressor.context_length:,} tokens (compress at {int(compression_threshold*100)}% = {self.context_compressor.threshold_tokens:,})")
             else:
                 print(f"📊 Context limit: {self.context_compressor.context_length:,} tokens (auto-compression disabled)")
+
+    def reset_session_state(self):
+        """Reset all session-scoped token counters to 0 for a fresh session.
+        
+        This method encapsulates the reset logic for all session-level metrics
+        including:
+        - Token usage counters (input, output, total, prompt, completion)
+        - Cache read/write tokens
+        - API call count
+        - Reasoning tokens
+        - Estimated cost tracking
+        - Context compressor internal counters
+        
+        The method safely handles optional attributes (e.g., context compressor)
+        using ``hasattr`` checks.
+        
+        This keeps the counter reset logic DRY and maintainable in one place
+        rather than scattering it across multiple methods.
+        """
+        # Token usage counters
+        self.session_total_tokens = 0
+        self.session_input_tokens = 0
+        self.session_output_tokens = 0
+        self.session_prompt_tokens = 0
+        self.session_completion_tokens = 0
+        self.session_cache_read_tokens = 0
+        self.session_cache_write_tokens = 0
+        self.session_reasoning_tokens = 0
+        self.session_api_calls = 0
+        self.session_estimated_cost_usd = 0.0
+        self.session_cost_status = "unknown"
+        self.session_cost_source = "none"
+        
+        # Context compressor internal counters (if present)
+        if hasattr(self, "context_compressor") and self.context_compressor:
+            self.context_compressor.last_prompt_tokens = 0
+            self.context_compressor.last_completion_tokens = 0
     
     @staticmethod
     def _safe_print(*args, **kwargs):