feat: 更新令牌估算逻辑，使用 JSON 序列化以匹配实际请求大小，并在当前话题处理器中添加令牌估算

src/agent/context_compressor.rs

@@ -11,31 +11,19 @@ use crate::agent::{AgentError, AgentRuntimeConfig};
 const TOKEN_ESTIMATE_CHARS_PER_TOKEN: usize = 4;
 const TOKEN_ESTIMATE_SAFETY_MULTIPLIER: f64 = 1.2;
 
-/// Token estimation using ~4 chars/token heuristic with 1.2x safety margin.
+/// Token estimation using JSON serialization (matches actual request size)
 pub fn estimate_tokens(messages: &[ChatMessage]) -> usize {
-    let raw: usize = messages
+    // Serialize to JSON to match actual request format sent to LLM
-        .iter()
+    let serialized_len = serde_json::to_string(messages)
-        .map(|message| {
+        .map(|s| s.len())
-            message
+        .unwrap_or_else(|_| {
-                .content
+            // Fallback: use content length if serialization fails
-                .len()
+            messages.iter().map(|m| m.content.len()).sum()
-                .div_ceil(TOKEN_ESTIMATE_CHARS_PER_TOKEN)
+        });
-                + estimate_image_tokens(&message.media_refs)
-                + 4
-        })
-        .sum();
-    (raw as f64 * TOKEN_ESTIMATE_SAFETY_MULTIPLIER) as usize
-}
 
-fn estimate_image_tokens(media_refs: &[String]) -> usize {
+    // Apply safety margin for token estimation
-    media_refs
+    ((serialized_len / TOKEN_ESTIMATE_CHARS_PER_TOKEN) as f64
-        .iter()
+        * TOKEN_ESTIMATE_SAFETY_MULTIPLIER) as usize
-        .filter_map(|path| std::fs::metadata(path).ok())
-        .map(|metadata| {
-            let base64_chars = metadata.len().saturating_mul(4).div_ceil(3) as usize;
-            base64_chars.div_ceil(TOKEN_ESTIMATE_CHARS_PER_TOKEN)
-        })
-        .sum()
 }
 
 /// Configuration for context compression.
@@ -502,13 +490,13 @@ mod tests {
         ];
 
         let tokens = estimate_tokens(&messages);
-        // "Hello" (5) -> ceil(5/4)+4 = 2+4 = 6
+        // JSON serialization includes: id, role, content, timestamp, etc.
-        // "Hi there!" (8) -> ceil(8/4)+4 = 2+4 = 6
+        // With 3 messages, the JSON overhead is significant
-        // "How are you?" (11) -> ceil(11/4)+4 = 3+4 = 7
+        // Serialized JSON is typically 300-500 chars for 3 simple messages
-        // raw = 19, with 1.2x = ~23
+        // 500 / 4 * 1.2 = ~150 tokens
         assert!(
-            tokens > 18 && tokens < 30,
+            tokens > 50 && tokens < 300,
-            "Expected ~23 tokens, got {}",
+            "Expected ~100-200 tokens (JSON overhead), got {}",
             tokens
         );
     }

src/command/handlers/get_current.rs

@@ -1,3 +1,4 @@
+use crate::agent::context_compressor::estimate_tokens;
 use crate::command::context::CommandContext;
 use crate::command::handler::{CommandHandler, CommandMetadata};
 use crate::command::response::{CommandError, CommandResponse, MessageKind};
@@ -56,14 +57,22 @@ async fn handle_get_current_session(
         .map_err(|e| CommandError::new("GET_TOPIC_ERROR", e.to_string()))?
         .ok_or_else(|| CommandError::new("TOPIC_NOT_FOUND", format!("Topic not found: {}", topic_id)))?;
 
+    // Load messages and estimate tokens
+    let messages = handler
+        .store
+        .load_messages_for_topic(topic_id)
+        .map_err(|e| CommandError::new("LOAD_MESSAGES_ERROR", e.to_string()))?;
+    let estimated_tokens = estimate_tokens(&messages);
+
     let last_active = format_time_ago(topic.last_active_at);
     let created_at = format_time_ago(topic.created_at);
 
     let message = format!(
-        "Current Topic:\n\n  Topic ID: {}\n  Title: {}\n  Messages: {}\n  Created: {}\n  Last Active: {}",
+        "Current Topic:\n\n  Topic ID: {}\n  Title: {}\n  Messages: {}\n  Tokens: ~{}\n  Created: {}\n  Last Active: {}",
         topic.id,
         topic.title,
         topic.message_count,
+        estimated_tokens,
         created_at,
         last_active
     );
@@ -72,7 +81,8 @@ async fn handle_get_current_session(
         .with_message(MessageKind::Notification, &message)
         .with_metadata("topic_id", &topic.id)
         .with_metadata("title", &topic.title)
-        .with_metadata("message_count", &topic.message_count.to_string()))
+        .with_metadata("message_count", &topic.message_count.to_string())
+        .with_metadata("estimated_tokens", &estimated_tokens.to_string()))
 }
 
 fn format_time_ago(timestamp_ms: i64) -> String {