修复: DeepSeek 400 全量扫描 + 队列 per-conv 隔离

- openai_compat: 扫描所有 assistant 消息剥离 orphan tool_calls（原仅查末条）
- queue 加 conversationId 字段，按会话精准 drain
- regenerate/editMessage 只清本会话排队消息
- newConversation 保留旧会话排队消息
- AiError 只清出错会话的队列项

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

@@ -77,6 +77,8 @@ fn system_prompt_parts(lang: &str) -> (&'static str, &'static str, &'static str)
              - Ask for clarification if the user's intent is unclear\n\
              - Prefer using tools to complete actions rather than just describing steps\n\
              - When a tool call fails, clearly tell the user it failed and why. Never disguise a fallback action as the original intent's success (e.g. don't write to description to fake a directory binding), and never falsely report success\n\
+             - **Self-check before claiming completion**: Before announcing a task done, verify the result matches the original intent (grep key references / read back field values / cross-check). Fix discrepancies before declaring success; never claim all done without verification (repeatedly observed: missed reference renames, fields silently overwritten by later ops, forcing the user to manually verify)\n\
+             - **Duplicate call detection**: If a tool (e.g. read_file/search_files) has already been called with identical arguments and returned successfully, do not call it again — the result is already in the conversation history; review the context instead of re-executing\n\
              ## Focus\n\
              - Always center your response on the core goal of the user's current request; the previous round's topic is only background, not the current task.\n\
              - When the user switches topics (a clear new intent), follow the latest request; do not drag the old topic into the new answer.\n\
@@ -101,6 +103,8 @@ fn system_prompt_parts(lang: &str) -> (&'static str, &'static str, &'static str)
              - 如果不确定用户意图，先提问\n\
              - 优先使用工具完成操作，而不是只描述步骤\n\
              - 工具调用失败时必须明确告知用户失败原因，严禁用替代操作冒充原意图成功（如绑定目录失败不得改写描述冒充已绑定），也绝不谎报成功\n\
+             - **宣称任务完成前必须自检**：用 grep/读取关键引用/核对字段值等方式验证结果与原意图一致，发现偏差先修正再宣布完成；严禁不验证就宣称「全部完成」（实测反复出现：漏改引用名、字段被后续操作覆盖未发现，被迫用户人工核对）\n\
+             - **重复调用检测**：如果某个工具（如 read_file/search_files）已用相同参数调用过且返回成功，不要重复调用——会话历史里已有结果，回顾上下文而非重复执行\n\
              ## 聚焦准则\n\
              - 始终围绕用户当前请求的核心目标回答；上一轮的主题只是背景，不是当前任务。\n\
              - 用户切换话题（明显的新意图）时，以最新请求为准，不要把旧话题带进新回答。\n\