diff --git a/crates/df-ai/src/coordinator.rs b/crates/df-ai/src/coordinator.rs
index ebb4273..cffe9d2 100644
--- a/crates/df-ai/src/coordinator.rs
+++ b/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]
diff --git a/src-tauri/src/commands/ai/agentic/command_lock.rs b/src-tauri/src/commands/ai/agentic/command_lock.rs
new file mode 100644
index 0000000..4026c40
--- /dev/null
+++ b/src-tauri/src/commands/ai/agentic/command_lock.rs
@@ -0,0 +1,134 @@
+//! 命令执行互斥锁 — 防止多 Agent 并行时同目录的同名命令资源竞争
+//!
+//! 设计依据:docs/02-架构设计/专项设计/多Agent并行执行与仲裁合并设计-2026-07-01.md §4.3
+//!
+//! 场景:多 Agent 并行时,两个 SubTask 同时跑 `npm install` 争抢 node_modules。
+//! 方案:按 (working_dir, command_name) 加 mutex,同 key 串行化。
+
+use std::collections::HashMap;
+use std::sync::{Arc, Mutex};
+use tokio::sync::Semaphore;
+
+/// 全局命令锁注册表
+/// key = "{working_dir}::{command_first_word}"
+/// 每个 key 一个 Semaphore(1),同 key 并发请求串行化
+#[allow(dead_code)]
+#[derive(Debug, Clone)]
+pub struct CommandLockRegistry {
+    inner: Arc<Mutex<HashMap<String, Arc<Semaphore>>>>,
+}
+
+impl CommandLockRegistry {
+    #[allow(dead_code)]
+    pub fn new() -> Self {
+        Self {
+            inner: Arc::new(Mutex::new(HashMap::new())),
+        }
+    }
+
+    /// 获取(或创建)指定 key 的信号量。
+    /// 返回 Arc<Semaphore>,调用方 await acquire 后执行命令,drop permit 后释放。
+    #[allow(dead_code)]
+    pub fn get_or_create(&self, working_dir: &str, command: &str) -> Arc<Semaphore> {
+        let cmd_first = command.split_whitespace().next().unwrap_or(command);
+        let key = format!("{}::{}", working_dir, cmd_first);
+        let mut guard = self.inner.lock().unwrap();
+        guard
+            .entry(key)
+            .or_insert_with(|| Arc::new(Semaphore::new(1)))
+            .clone()
+    }
+
+    /// 当前注册的锁数量(调试/监控用)
+    #[allow(dead_code)]
+    pub fn lock_count(&self) -> usize {
+        self.inner.lock().unwrap().len()
+    }
+}
+
+impl Default for CommandLockRegistry {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[tokio::test]
+    async fn lck_01_same_dir_same_cmd_serialized() {
+        let registry = CommandLockRegistry::new();
+        let sem1 = registry.get_or_create("/project", "npm install");
+        let sem2 = registry.get_or_create("/project", "npm install");
+
+        // 同 key 应返回同一个 Semaphore
+        assert!(Arc::ptr_eq(&sem1, &sem2), "同 dir+cmd 应返回同一个 Semaphore");
+
+        // 获取第一个 permit
+        let permit1 = sem1.acquire().await.unwrap();
+        // 第二个应等待(非阻塞测试:try_acquire 应失败)
+        let try_result = sem2.try_acquire();
+        assert!(try_result.is_err(), "同 key 第二个应被阻塞");
+
+        drop(permit1);
+        // 释放后第二个应能获取
+        let permit2 = sem2.acquire().await;
+        assert!(permit2.is_ok(), "释放后应可获取");
+    }
+
+    #[tokio::test]
+    async fn lck_02_different_cmds_parallel() {
+        let registry = CommandLockRegistry::new();
+        let npm_sem = registry.get_or_create("/project", "npm install");
+        let cargo_sem = registry.get_or_create("/project", "cargo build");
+
+        // 不同命令应是不同的 Semaphore
+        assert!(!Arc::ptr_eq(&npm_sem, &cargo_sem), "不同 cmd 应是不同 Semaphore");
+
+        // 两个都能同时获取
+        let p1 = npm_sem.acquire().await.unwrap();
+        let p2 = cargo_sem.acquire().await.unwrap();
+        drop(p1);
+        drop(p2);
+    }
+
+    #[tokio::test]
+    async fn lck_03_different_dirs_parallel() {
+        let registry = CommandLockRegistry::new();
+        let sem1 = registry.get_or_create("/project-a", "npm install");
+        let sem2 = registry.get_or_create("/project-b", "npm install");
+
+        // 不同目录应是不同的 Semaphore
+        assert!(!Arc::ptr_eq(&sem1, &sem2), "不同 dir 应是不同 Semaphore");
+
+        // 两个都能同时获取
+        let p1 = sem1.acquire().await.unwrap();
+        let p2 = sem2.acquire().await.unwrap();
+        drop(p1);
+        drop(p2);
+    }
+
+    #[tokio::test]
+    async fn lck_04_command_extracted_first_word() {
+        let registry = CommandLockRegistry::new();
+        let sem1 = registry.get_or_create("/proj", "npm install --force");
+        let sem2 = registry.get_or_create("/proj", "npm run build");
+
+        // "npm install --force" 和 "npm run build" 首词都是 "npm"
+        // 同 dir + 同首词应串行化
+        assert!(Arc::ptr_eq(&sem1, &sem2), "同 dir+同首词应串行化");
+    }
+
+    #[test]
+    fn lck_05_lock_count_tracks_keys() {
+        let registry = CommandLockRegistry::new();
+        assert_eq!(registry.lock_count(), 0);
+        registry.get_or_create("/a", "npm");
+        assert_eq!(registry.lock_count(), 1);
+        registry.get_or_create("/a", "cargo");
+        assert_eq!(registry.lock_count(), 2);
+        registry.get_or_create("/a", "npm"); // 已存在
+        assert_eq!(registry.lock_count(), 2);
+    }
+}
diff --git a/src-tauri/src/commands/ai/agentic/mod.rs b/src-tauri/src/commands/ai/agentic/mod.rs
index 48a6ee2..8695aba 100644
--- a/src-tauri/src/commands/ai/agentic/mod.rs
+++ b/src-tauri/src/commands/ai/agentic/mod.rs
@@ -271,6 +271,7 @@ mod knowledge_lifecycle;
 //   - 兜底:状态机层迁移失败(非法转换)记 warn 不 panic,核心生成态复位仍经 enum 迁移收敛。
 // ============================================================
 pub mod conv_state;
+pub mod command_lock;
 
 // ============================================================
 // F-260614-04 / F-260614-04b: 单 Provider 流式结果 + fallback 辅助
diff --git a/src-tauri/src/commands/settings.rs b/src-tauri/src/commands/settings.rs
index 3857732..10dbbb3 100644
--- a/src-tauri/src/commands/settings.rs
+++ b/src-tauri/src/commands/settings.rs
@@ -140,3 +140,45 @@ pub async fn set_plan_execution(enabled: bool) -> Result<(), String> {
 pub async fn get_plan_execution() -> Result<bool, String> {
     Ok(df_ai::plan_executor::plan_execution_enabled())
 }
+
+/// 解决合并冲突(用户/reviewer 选择解决方案后调用)。
+///
+/// 更新 ai_conflicts 表的 resolution + resolved_by + resolved_at,
+/// 并 emit AiConflictResolved 事件供前端更新徽章。
+#[tauri::command]
+pub async fn resolve_conflict(
+    state: State<'_, AppState>,
+    app_handle: tauri::AppHandle,
+    conflict_id: String,
+    plan_id: String,
+    resolution: String,
+    resolved_by: String,
+    conversation_id: Option<String>,
+) -> Result<(), String> {
+    use tauri::Emitter;
+    let repo = df_storage::crud::ConflictRepo::new(&state.db);
+    let now = df_types::now_millis().to_string();
+    let ok = repo.resolve(&conflict_id, &resolution, &resolved_by, &now)
+        .await
+        .map_err(err_str)?;
+    if !ok {
+        return Err(format!("冲突 {} 不存在或已解决", conflict_id));
+    }
+    tracing::info!(
+        conflict_id = %conflict_id,
+        resolution = %resolution,
+        resolved_by = %resolved_by,
+        "[CONFLICT] 冲突已解决"
+    );
+    // emit AiConflictResolved 事件
+    let ev = crate::commands::ai::AiChatEvent::AiConflictResolved {
+        conflict_id,
+        plan_id,
+        resolution,
+        resolved_by,
+        conversation_id,
+    };
+    let _ = app_handle.emit("ai-chat-event", ev.clone());
+    let _ = state.ai_event_bus.publish_event(ev);
+    Ok(())
+}
diff --git a/src-tauri/src/lib.rs b/src-tauri/src/lib.rs
index 9f1b723..1736e9c 100644
--- a/src-tauri/src/lib.rs
+++ b/src-tauri/src/lib.rs
@@ -436,6 +436,8 @@ pub fn run() {
             // Plan 执行开关
             commands::settings::set_plan_execution,
             commands::settings::get_plan_execution,
+            // 冲突解决
+            commands::settings::resolve_conflict,
         ])
         .run(tauri::generate_context!())
         .expect("error while running tauri application");