重构: F-09 batch5 llm_concurrency会话级改造(决策c)

- state.rs: per_conv HashMap<conv_id,Semaphore>(每对话permits=2) + per_conv_permits热改 + acquire_per_conv(conv_id) + release_conv
- agentic.rs: loop入口acquire_global+acquire_per_conv(conv_id)整loop持有(会话级并发上限3) + 删每轮acquire/drop
- compress/title/knowledge_inject: acquire_per_conv(conv_id)+签名conv_id
- project.rs: 扫描合成key + ai_conversation_delete release_conv
global: LLM调用并发→并发会话数上限;F-260616-12 retry permit自洽
主代兜底: cargo check --workspace 0 + test 96 + grep印证

src-tauri/src/commands/ai/knowledge_inject.rs

@@ -388,8 +388,9 @@ async fn extract_knowledge_from_conversation(
         Err(e) => return Err(anyhow::anyhow!("provider 密钥不可用: {}", e)),
     };
     // LLM 并发限流（知识提炼属独立调用，纳入双层 Semaphore）
+    // F-09 B 批5: per_conv 改 HashMap<conv_id>,知识提炼针对本对话,用 conv_id 共享该 conv 限流槽。
     let _global_permit = llm_concurrency.acquire_global().await;
-    let _per_conv_permit = llm_concurrency.acquire_per_conv().await;
+    let _per_conv_permit = llm_concurrency.acquire_per_conv(conv_id).await;
     let resp = provider.complete(request).await?;
     let raw = resp.text.trim();