新增: 初始化 DevFlow 项目仓库

Tauri 2 + Vue 3 + Vite 6 桌面应用，Rust workspace 含 13 个 crate
(df-ai / df-storage / df-workflow / df-core / df-execute 等)。
核心能力：AI 聊天 agentic 循环(工具调用+人工审批)、工作流引擎、
任务/想法/项目/阶段管理、可追溯性，及配套前端组件。

crates/df-ai/src/provider.rs

@@ -0,0 +1,207 @@
+//! LLM Provider trait — 统一的 LLM 调用抽象
+//!
+//! 支持 OpenAI 兼容 API（覆盖 OpenAI / GLM / DeepSeek / Claude 兼容模式），
+//! 含 function calling / tool use 能力。
+
+use std::pin::Pin;
+
+use async_trait::async_trait;
+use futures::Stream;
+use serde::{Deserialize, Serialize};
+
+// ============================================================
+// 核心数据结构
+// ============================================================
+
+/// LLM 调用请求
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct CompletionRequest {
+    /// 模型名称
+    pub model: String,
+    /// 提示消息列表
+    pub messages: Vec<ChatMessage>,
+    /// 温度（0.0 ~ 2.0）
+    pub temperature: Option<f32>,
+    /// 最大生成 token 数
+    pub max_tokens: Option<u32>,
+    /// 是否流式输出
+    pub stream: bool,
+    /// 可调用的工具定义
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub tools: Option<Vec<ToolDefinition>>,
+    /// 工具调用策略: "auto" | "none" | {"type":"function","name":"xxx"}
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub tool_choice: Option<serde_json::Value>,
+}
+
+/// 聊天消息
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct ChatMessage {
+    pub role: MessageRole,
+    pub content: String,
+    /// 工具调用 ID（role=Tool 时必填）
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub tool_call_id: Option<String>,
+    /// AI 发起的工具调用列表（role=Assistant 时可能有）
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub tool_calls: Option<Vec<ToolCall>>,
+}
+
+impl ChatMessage {
+    pub fn system(content: impl Into<String>) -> Self {
+        Self { role: MessageRole::System, content: content.into(), tool_call_id: None, tool_calls: None }
+    }
+    pub fn user(content: impl Into<String>) -> Self {
+        Self { role: MessageRole::User, content: content.into(), tool_call_id: None, tool_calls: None }
+    }
+    pub fn assistant(content: impl Into<String>) -> Self {
+        Self { role: MessageRole::Assistant, content: content.into(), tool_call_id: None, tool_calls: None }
+    }
+    pub fn assistant_with_tools(content: impl Into<String>, tool_calls: Vec<ToolCall>) -> Self {
+        Self { role: MessageRole::Assistant, content: content.into(), tool_call_id: None, tool_calls: Some(tool_calls) }
+    }
+    pub fn tool_result(call_id: impl Into<String>, content: impl Into<String>) -> Self {
+        Self { role: MessageRole::Tool, content: content.into(), tool_call_id: Some(call_id.into()), tool_calls: None }
+    }
+}
+
+/// 消息角色
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(rename_all = "lowercase")]
+pub enum MessageRole {
+    System,
+    User,
+    Assistant,
+    Tool,
+}
+
+/// 工具定义
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct ToolDefinition {
+    #[serde(rename = "type")]
+    pub tool_type: String,
+    pub function: ToolFunction,
+}
+
+impl ToolDefinition {
+    pub fn function(name: impl Into<String>, description: impl Into<String>, parameters: serde_json::Value) -> Self {
+        Self {
+            tool_type: "function".into(),
+            function: ToolFunction { name: name.into(), description: description.into(), parameters },
+        }
+    }
+}
+
+/// 函数定义
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct ToolFunction {
+    pub name: String,
+    pub description: String,
+    pub parameters: serde_json::Value,
+}
+
+/// 工具调用（AI 发起）
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct ToolCall {
+    pub id: String,
+    #[serde(rename = "type")]
+    pub call_type: String,
+    pub function: ToolCallFunction,
+}
+
+impl ToolCall {
+    pub fn new(id: impl Into<String>, name: impl Into<String>, arguments: impl Into<String>) -> Self {
+        Self {
+            id: id.into(),
+            call_type: "function".into(),
+            function: ToolCallFunction { name: name.into(), arguments: arguments.into() },
+        }
+    }
+}
+
+/// 工具调用函数部分
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct ToolCallFunction {
+    pub name: String,
+    pub arguments: String,
+}
+
+/// LLM 调用响应
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct CompletionResponse {
+    /// 生成的文本
+    pub text: String,
+    /// 使用的模型
+    pub model: String,
+    /// 消耗的 token 数
+    pub usage: TokenUsage,
+    /// AI 发起的工具调用（如有）
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub tool_calls: Option<Vec<ToolCall>>,
+}
+
+/// Token 用量
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct TokenUsage {
+    pub prompt_tokens: u32,
+    pub completion_tokens: u32,
+    pub total_tokens: u32,
+}
+
+/// Provider 支持的特性标志
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct ProviderFeatures {
+    pub streaming: bool,
+    pub function_calling: bool,
+    pub vision: bool,
+}
+
+/// 流式输出的 chunk
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct StreamChunk {
+    /// 增量文本
+    pub delta: String,
+    /// 是否结束
+    pub finished: bool,
+    /// 工具调用增量（如有）
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub tool_calls: Option<Vec<ToolCallDelta>>,
+}
+
+/// 工具调用增量（流式中的片段）
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct ToolCallDelta {
+    /// 索引
+    pub index: u32,
+    /// 工具调用 ID（仅第一个 chunk 有）
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub id: Option<String>,
+    /// 函数名片段
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub function_name: Option<String>,
+    /// 函数参数片段
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub function_arguments: Option<String>,
+}
+
+/// 异步流类型别名
+pub type StreamResult = Pin<Box<dyn Stream<Item = anyhow::Result<StreamChunk>> + Send>>;
+
+/// LLM Provider trait
+#[async_trait]
+pub trait LlmProvider: Send + Sync {
+    /// 同步调用
+    async fn complete(&self, request: CompletionRequest) -> anyhow::Result<CompletionResponse>;
+
+    /// 流式调用（返回异步流）
+    async fn stream(
+        &self,
+        request: CompletionRequest,
+    ) -> anyhow::Result<StreamResult>;
+
+    /// Provider 名称
+    fn name(&self) -> &str;
+
+    /// 支持的特性
+    fn supported_features(&self) -> ProviderFeatures;
+}