重构: F-09批2 调用方迁移per-conv(双写桥接共存期)

- agentic.rs: GeneratingGuard加conv_id + 三处退出校验改conv存在性(决策e) + stop_flag/notify/messages/iteration per-conv + try_continue加conv_id参数
- commands.rs: IPC写路径双写桥接(per_conv新真相源+顶层双写,批4删) + ai_is_generating读per_conv fallback顶层
- audit/conversation/title/knowledge_inject/lib.rs: per_conv读写迁移
- conv()/conv_read()去allow(批2有调用方)
共存期双写: per_conv主+顶层双写兼容批4前IPC,批4签名改后删顶层
主代兜底: cargo check --workspace 0 + test 96 passed + grep三处退出/GeneratingGuard/双写印证

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

@@ -43,24 +43,48 @@ pub(crate) async fn ensure_conversation_title(
     }
 
     // 取对话文本（仅 user/assistant，跳过 tool 噪音），取前 6 条供 LLM 总结
+    // F-260616-09 B 批2:读 per_conv.messages(conv_id 来源:本函数入参)。
+    //   per_conv 未建时 fallback 顶层(switch 触发的 spawn_ensure_title 可能无 per_conv)。
     let (summary_msgs, all_msgs) = {
         let session = session_arc.lock().await;
-        let summary: Vec<ChatMessage> = session.messages.iter()
-            .filter(|m| matches!(m.role, MessageRole::User | MessageRole::Assistant))
-            .take(6)
-            .map(|m| ChatMessage {
-                role: m.role.clone(),
-                content: m.content.clone(),
-                parts: None,
-                tool_call_id: None,
-                tool_calls: None,
-                model: None,
-                status: None,
-                reasoning_content: m.reasoning_content.clone(),
-                timestamp: m.timestamp,
-            })
-            .collect();
-        (summary, session.messages.all_messages_clone())
+        let conv = session.conv_read(conv_id);
+        let summary: Vec<ChatMessage> = match conv {
+            Some(c) => c.messages.iter()
+                .filter(|m| matches!(m.role, MessageRole::User | MessageRole::Assistant))
+                .take(6)
+                .map(|m| ChatMessage {
+                    role: m.role.clone(),
+                    content: m.content.clone(),
+                    parts: None,
+                    tool_call_id: None,
+                    tool_calls: None,
+                    model: None,
+                    status: None,
+                    reasoning_content: m.reasoning_content.clone(),
+                    timestamp: m.timestamp,
+                })
+                .collect(),
+            None => session.messages.iter()
+                .filter(|m| matches!(m.role, MessageRole::User | MessageRole::Assistant))
+                .take(6)
+                .map(|m| ChatMessage {
+                    role: m.role.clone(),
+                    content: m.content.clone(),
+                    parts: None,
+                    tool_call_id: None,
+                    tool_calls: None,
+                    model: None,
+                    status: None,
+                    reasoning_content: m.reasoning_content.clone(),
+                    timestamp: m.timestamp,
+                })
+                .collect(),
+        };
+        let all_msgs = match conv {
+            Some(c) => c.messages.all_messages_clone(),
+            None => session.messages.all_messages_clone(),
+        };
+        (summary, all_msgs)
     };
     if summary_msgs.is_empty() {
         return;