新增: 上下文管理演进 Wave1（契约定义 + T1动态阈值 + T2命名空间）

Agent 3: 共享契约类型定义
- CompressedSummary（T3输出格式）
- WorkflowContextBlock（T4工作流DAG上下文）
- WorkingContext + GoalItem/DecisionItem/StepInfo（T5常驻上下文）
- 脏标记版本追踪 + reset_all 压缩联动

T1: 动态压缩阈值
- maybe_auto_compress 加 sys_tokens 参数，触发条件从 budget*0.6 改为 available*0.6
- 调用处传 sys_tokens（loop顶部已缓存）
- 3 行核心改动

T2: 工具命名空间存储
- crates/df-ai/src/namespace_store.rs: 完整实现 + 单元测试
- process_tool_calls: Low/Med/High 路径 namespace 路由
- save_conversation: namespace 引用展开为原文再落 DB
- AiSession 新增 namespace_store 字段

crates/df-ai/src/context_helpers.rs

@@ -1,4 +1,4 @@
-//! 上下文管理纯函数与数据类型 — 从 context.rs 抽离的无 `self` 依赖部分
+//! 上下文管理纯函数与数据类型 — 从 context.rs 抽离的无 `self` 依赖部分
 //!
 //! 职责：
 //! - Token 粗估器（字符级近似，无 tokenizer 依赖）
@@ -553,6 +553,9 @@ pub const TOOL_MISSING_PREFIX: &str = "tool_missing_";
 /// 兜底:sanitize view-only 不改持久化,失败只影响单请求,flag 关→行为完全等价改动前。
 pub const PLACEHOLDER_INTEGRITY_ENABLED: bool = true;
 
+/// namespace 引用路径前缀（转发至 namespace_store,供 context.rs 统一路径引用）
+pub const NAMESPACE_REF_PREFIX: &str = crate::namespace_store::NAMESPACE_REF_PREFIX;
+
 /// 占位 tool_result 内容中嵌入的唯一标记前缀(供 sanitize 识别"审批挂起占位,不可裁")。
 ///
 /// 写入处(audit/cache.rs:PENDING_APPROVAL_PLACEHOLDER)格式:`{占位文本}{__PENDING__}{tc_id}`,
@@ -604,6 +607,169 @@ pub fn extract_pending_tc_id(content: &str) -> Option<&str> {
         .filter(|id| !id.is_empty())
 }
 
+
+// ============================================================
+// Wave 共享契约类型（由 上下文管理演进-执行计划 Agent 3 定义）
+// ============================================================
+
+/// 压缩摘要双格式（T3 输出, T5 消费）
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct CompressedSummary {
+    /// JSON 卡片序列化（主题/决策/待办/token节省）
+    pub json_card: String,
+    /// 自然语言摘要（向前兼容关键词兜底降级）
+    pub nl_summary: String,
+}
+
+/// 工作流 DAG 上下文块（T4 输出 → 注入 system prompt）
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct WorkflowContextBlock {
+    pub workflow_id: String,
+    pub workflow_name: String,
+    pub total_nodes: usize,
+    pub completed_nodes: usize,
+    pub current_node: Option<String>,
+    pub next_nodes: Vec<String>,
+}
+
+impl WorkflowContextBlock {
+    /// 格式化为 system prompt 可读文本
+    pub fn to_system_text(&self) -> String {
+        let mut s = format!("工作流: {} (ID: {})", self.workflow_name, self.workflow_id);
+        s.push_str(&format!("\n进度: {}/{}", self.completed_nodes, self.total_nodes));
+        if let Some(ref cur) = self.current_node {
+            s.push_str(&format!("\n当前步骤: {}", cur));
+        }
+        if !self.next_nodes.is_empty() {
+            s.push_str(&format!("\n后续: {}", self.next_nodes.join(" → ")));
+        }
+        s
+    }
+}
+
+/// 目标状态（T5 WorkingContext）
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub enum GoalStatus {
+    Active,
+    Completed,
+    Cancelled,
+}
+
+/// 步骤状态
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub enum StepStatus {
+    Pending,
+    InProgress,
+    Done,
+    Blocked,
+}
+
+/// 目标条目
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct GoalItem {
+    pub id: String,
+    pub text: String,
+    pub status: GoalStatus,
+}
+
+/// 决策条目
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct DecisionItem {
+    pub question: String,
+    pub decision: String,
+    pub reason: String,
+}
+
+/// 步骤信息
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct StepInfo {
+    pub step_name: String,
+    pub status: StepStatus,
+}
+
+/// WorkingContext 版本号（脏标记追踪）
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct WorkingContextVersion {
+    pub goals_changed_at: u32,
+    pub decisions_changed_at: u32,
+    pub unresolved_changed_at: u32,
+    pub step_changed_at: u32,
+    pub current_turn: u32,
+}
+
+impl WorkingContextVersion {
+    pub fn new() -> Self {
+        Self {
+            goals_changed_at: 0,
+            decisions_changed_at: 0,
+            unresolved_changed_at: 0,
+            step_changed_at: 0,
+            current_turn: 0,
+        }
+    }
+
+    /// 压缩后重置：将所有字段标记为本轮变更
+    pub fn reset_all(&mut self, _summary: &str, current_turn: u32) {
+        self.goals_changed_at = current_turn;
+        self.decisions_changed_at = current_turn;
+        self.unresolved_changed_at = current_turn;
+        self.current_turn = current_turn;
+    }
+}
+
+/// WorkingContext 常驻上下文（T5 实现）
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct WorkingContext {
+    pub goals: Vec<GoalItem>,
+    pub decisions: Vec<DecisionItem>,
+    pub unresolved: Vec<String>,
+    pub current_step: Option<StepInfo>,
+    pub version: WorkingContextVersion,
+}
+
+impl WorkingContext {
+    pub fn new() -> Self {
+        Self {
+            goals: Vec::new(),
+            decisions: Vec::new(),
+            unresolved: Vec::new(),
+            current_step: None,
+            version: WorkingContextVersion::new(),
+        }
+    }
+
+    /// 构建本轮需要注入的 L1 内容（L1a 必带 + L1b 条件注入）
+    pub fn build_injection(&self, recent_turns: u32) -> String {
+        let mut parts: Vec<String> = Vec::new();
+
+        // L1a: 当前步骤（每轮必带）
+        if let Some(ref step) = self.current_step {
+            parts.push(format!("当前步骤: {} [{:?}]", step.step_name, step.status));
+        }
+
+        // L1b: 过去 N 轮内有变更才注入
+        let threshold = self.version.current_turn.saturating_sub(recent_turns);
+        let has_active = self.goals.iter().any(|g| g.status == GoalStatus::Active);
+        if has_active && self.version.goals_changed_at >= threshold {
+            let active: Vec<&str> = self.goals.iter()
+                .filter(|g| g.status == GoalStatus::Active)
+                .map(|g| g.text.as_str())
+                .collect();
+            parts.push(format!("目标({}): {}", active.len(), active.join("; ")));
+        }
+        if self.version.decisions_changed_at >= threshold && !self.decisions.is_empty() {
+            let recent: Vec<&str> = self.decisions.iter().map(|d| d.decision.as_str()).collect();
+            parts.push(format!("近期决策: {}", recent.join("; ")));
+        }
+        if self.version.unresolved_changed_at >= threshold && !self.unresolved.is_empty() {
+            parts.push(format!("待解: {}", self.unresolved.join("; ")));
+        }
+
+        parts.join("\n")
+    }
+}
+
+
 #[cfg(test)]
 mod tests {
     use super::*;