修复: token 汇总正确性(会话级双计/is_estimated跨端/流式usage传递) + is_estimated SELECT 缺失修复

crates/df-ai/src/anthropic_helpers.rs

@@ -165,7 +165,7 @@ pub(crate) fn apply_anthropic_event(data: &str, usage_accum: &mut Option<TokenUs
                     reasoning_tokens: 0,
                 });
             }
-            StreamChunk { delta: String::new(), finished: false, tool_calls: None, usage: None, error: None, reasoning_content: None }
+            StreamChunk { delta: String::new(), finished: false, tool_calls: None, usage: usage_accum.clone(), error: None, reasoning_content: None }
         }
         // 消息增量：output_tokens 是累计值（非增量），直接覆盖 completion + 重算 total
         "message_delta" => {
@@ -173,9 +173,11 @@ pub(crate) fn apply_anthropic_event(data: &str, usage_accum: &mut Option<TokenUs
                 let acc = usage_accum
                     .get_or_insert(TokenUsage::default());
                 acc.completion_tokens = out as u32;
-                acc.total_tokens = acc.prompt_tokens + acc.completion_tokens;
+                acc.total_tokens = acc.prompt_tokens.saturating_add(acc.completion_tokens);
             }
-            StreamChunk { delta: String::new(), finished: false, tool_calls: None, usage: None, error: None, reasoning_content: None }
+            // 加固:usage 挂到本帧(而非仅 message_stop 带出),中途断连/端点不发 message_stop
+            // 时仍能拿到真实 usage,对称 openai_helpers 的修复。
+            StreamChunk { delta: String::new(), finished: false, tool_calls: None, usage: usage_accum.clone(), error: None, reasoning_content: None }
         }
         // 文本增量
         "content_block_delta" => {