新增: Reviewer仲裁+命令互斥锁+冲突解决IPC(批次C散项)

- coordinator: arbitrate_conflicts 方法(规则仲裁:成功方优先/双方成功推荐合并/都失败手动)

- coordinator: ConflictItem 加 subtask_a/subtask_b/recommendation 字段 + ConflictResolution 枚举

- command_lock.rs: CommandLockRegistry (dir+cmd首词 Semaphore 串行化,5个测试全绿)

- resolve_conflict IPC: 解决冲突→更新DB→emit AiConflictResolved 事件闭环

- 3个仲裁测试 + 5个互斥锁测试全绿

- 零编译警告

crates/df-ai/src/coordinator.rs

@@ -123,6 +123,35 @@ pub struct ConflictItem {
     pub file: String,
     /// 冲突描述
     pub description: String,
+    /// 冲突双方 SubTask id
+    pub subtask_a: Option<String>,
+    pub subtask_b: Option<String>,
+    /// Reviewer 仲裁推荐(Phase 2 LLM 仲裁填充)
+    pub recommendation: Option<ConflictResolution>,
+}
+
+/// 冲突解决方案
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum ConflictResolution {
+    /// 接受 A 的改动
+    AcceptA,
+    /// 接受 B 的改动
+    AcceptB,
+    /// 合并两者
+    Merged,
+    /// 用户手动处理
+    Manual,
+}
+
+impl ConflictResolution {
+    pub fn as_str(&self) -> &'static str {
+        match self {
+            Self::AcceptA => "a",
+            Self::AcceptB => "b",
+            Self::Merged => "merged",
+            Self::Manual => "manual",
+        }
+    }
 }
 
 // ---- Coordinator 实现 --------------------------------------------------------
@@ -445,11 +474,49 @@ impl Coordinator {
                         subtasks.len(),
                         subtasks.join(", ")
                     ),
+                    subtask_a: subtasks.first().cloned(),
+                    subtask_b: subtasks.get(1).cloned(),
+                    recommendation: None,
                 });
             }
         }
         conflicts
     }
+
+    /// 仲裁冲突:对每个冲突给出推荐解决方案
+    ///
+    /// Phase 1:规则驱动(简单启发式)
+    /// - 只有一方成功的冲突 → 推荐成功方
+    /// - 两方都成功 → 推荐 Merged(需人工确认)
+    /// - 无法判断 → Manual(留给用户)
+    ///
+    /// Phase 2 预留:LLM 驱动(读 diff → 推荐方案 + 理由)
+    pub fn arbitrate_conflicts(
+        &self,
+        conflicts: &mut [ConflictItem],
+        results: &[ExecutionResult],
+    ) {
+        let success_ids: std::collections::HashSet<&str> =
+            results.iter().filter(|r| r.success).map(|r| r.subtask_id.as_str()).collect();
+
+        for c in conflicts.iter_mut() {
+            let a_ok = c.subtask_a.as_deref().map(|id| success_ids.contains(id)).unwrap_or(false);
+            let b_ok = c.subtask_b.as_deref().map(|id| success_ids.contains(id)).unwrap_or(false);
+
+            c.recommendation = Some(match (a_ok, b_ok) {
+                (true, false) => ConflictResolution::AcceptA,
+                (false, true) => ConflictResolution::AcceptB,
+                (true, true) => ConflictResolution::Merged,
+                (false, false) => ConflictResolution::Manual,
+            });
+
+            tracing::info!(
+                file = %c.file,
+                recommendation = ?c.recommendation,
+                "[REVIEWER] 冲突仲裁推荐"
+            );
+        }
+    }
 }
 
 /// 从执行产出文本中提取被写入的文件路径(简化检测:匹配 write_file/patch_file 后的路径)
@@ -785,6 +852,62 @@ mod tests {
         assert!(files.is_empty());
     }
 
+    // -- Reviewer 仲裁 --
+
+    #[test]
+    fn arb_01_both_success_recommends_merged() {
+        let coord = make_coord();
+        let mut conflicts = vec![ConflictItem {
+            file: "main.rs".into(),
+            description: "冲突".into(),
+            subtask_a: Some("A".into()),
+            subtask_b: Some("B".into()),
+            recommendation: None,
+        }];
+        let results = vec![
+            ExecutionResult { subtask_id: "A".into(), persona_id: "coder".into(), output: "".into(), success: true },
+            ExecutionResult { subtask_id: "B".into(), persona_id: "coder".into(), output: "".into(), success: true },
+        ];
+        coord.arbitrate_conflicts(&mut conflicts, &results);
+        assert_eq!(conflicts[0].recommendation, Some(ConflictResolution::Merged));
+    }
+
+    #[test]
+    fn arb_02_a_failed_recommends_b() {
+        let coord = make_coord();
+        let mut conflicts = vec![ConflictItem {
+            file: "main.rs".into(),
+            description: "冲突".into(),
+            subtask_a: Some("A".into()),
+            subtask_b: Some("B".into()),
+            recommendation: None,
+        }];
+        let results = vec![
+            ExecutionResult { subtask_id: "A".into(), persona_id: "coder".into(), output: "".into(), success: false },
+            ExecutionResult { subtask_id: "B".into(), persona_id: "coder".into(), output: "".into(), success: true },
+        ];
+        coord.arbitrate_conflicts(&mut conflicts, &results);
+        assert_eq!(conflicts[0].recommendation, Some(ConflictResolution::AcceptB));
+    }
+
+    #[test]
+    fn arb_03_both_failed_recommends_manual() {
+        let coord = make_coord();
+        let mut conflicts = vec![ConflictItem {
+            file: "main.rs".into(),
+            description: "冲突".into(),
+            subtask_a: Some("A".into()),
+            subtask_b: Some("B".into()),
+            recommendation: None,
+        }];
+        let results = vec![
+            ExecutionResult { subtask_id: "A".into(), persona_id: "coder".into(), output: "".into(), success: false },
+            ExecutionResult { subtask_id: "B".into(), persona_id: "coder".into(), output: "".into(), success: false },
+        ];
+        coord.arbitrate_conflicts(&mut conflicts, &results);
+        assert_eq!(conflicts[0].recommendation, Some(ConflictResolution::Manual));
+    }
+
     // -- DispatchStrategy --
 
     #[test]