diff --git a/crates/df-ai/src/context/manager_tests.rs b/crates/df-ai/src/context/manager_tests.rs
index 93c5d13..96fb4c8 100644
--- a/crates/df-ai/src/context/manager_tests.rs
+++ b/crates/df-ai/src/context/manager_tests.rs
@@ -282,8 +282,8 @@ fn compress_old_messages_marks_compressed_and_returns_refs() {
     assert_eq!(compressed[1].content, "旧回复1");
 
     // status 已改 compressed
-    assert_eq!(mgr.messages_mut()[0].message.status.as_deref(), Some("compressed"));
-    assert_eq!(mgr.messages_mut()[1].message.status.as_deref(), Some("compressed"));
+    assert_eq!(mgr.messages_mut()[0].message.status.as_ref(), Some(&MessageStatus::Compressed));
+    assert_eq!(mgr.messages_mut()[1].message.status.as_ref(), Some(&MessageStatus::Compressed));
     // 保护区外(本例 index 2)仍 active
     assert!(mgr.messages_mut()[2].message.is_active(), "保护区外消息不应被动");
 
@@ -346,8 +346,8 @@ fn compress_old_messages_skips_already_inactive() {
     );
     // truncated 状态不被改成 compressed(保留原 truncated,语义不混淆)
     assert_eq!(
-        mgr.messages_mut()[0].message.status.as_deref(),
-        Some("truncated"),
+        mgr.messages_mut()[0].message.status.as_ref(),
+        Some(&MessageStatus::Truncated),
         "已 truncated 不应被改写为 compressed"
     );
 }
@@ -660,7 +660,7 @@ fn topic_field_survives_compress_old_messages() {
     assert_eq!(mgr.messages_mut()[0].topic.as_deref(), Some("code"), "compressed 消息 topic 应保留");
     assert_eq!(mgr.messages_mut()[1].topic.as_deref(), Some("file"), "compressed 消息 topic 应保留");
     // status 改为 compressed
-    assert_eq!(mgr.messages_mut()[0].message.status.as_deref(), Some("compressed"));
+    assert_eq!(mgr.messages_mut()[0].message.status.as_ref(), Some(&MessageStatus::Compressed));
 }
 
 #[test]
diff --git a/crates/df-nodes/src/human_node.rs b/crates/df-nodes/src/human_node.rs
index e9e40a0..e33aea0 100644
--- a/crates/df-nodes/src/human_node.rs
+++ b/crates/df-nodes/src/human_node.rs
@@ -218,7 +218,7 @@ mod tests {
             node_id: node_id.to_string(),
             inputs: HashMap::new(),
             config,
-            execution_id: execution_id.to_string(),
+            execution_id: execution_id.into(),
             event_bus: event_bus.clone(),
             node_status: StateMachine::new(),
         }
@@ -235,7 +235,7 @@ mod tests {
     ) {
         event_bus
             .send(WorkflowEvent::HumanApprovalResponse {
-                execution_id: execution_id.to_string(),
+                execution_id: execution_id.into(),
                 node_id: node_id.to_string(),
                 decision: decision.to_string(),
                 decisions: vec![],
@@ -254,7 +254,7 @@ mod tests {
     ) {
         event_bus
             .send(WorkflowEvent::HumanApprovalResponse {
-                execution_id: execution_id.to_string(),
+                execution_id: execution_id.into(),
                 node_id: node_id.to_string(),
                 decision: String::new(),
                 decisions: decisions.iter().map(|s| s.to_string()).collect(),
@@ -477,8 +477,8 @@ mod tests {
         dag.add_node("b".to_string(), Box::new(HumanNode));
         dag.add_edge("a".to_string(), "b".to_string());
 
-        let mut executor = DagExecutor::new(bus.clone(), exec_id.to_string());
-        let sm = executor.state_machine(); // 共享状态机（spawn 后仍可读）
+        let mut executor = DagExecutor::new(bus.clone(), exec_id.into());
+        let sm = executor.state_machine(); // 共享状态机(spawn 后仍可读)
 
         let run_handle = tokio::spawn(async move {
             executor
@@ -537,7 +537,7 @@ mod tests {
         let mut dag = Dag::new();
         dag.add_node("h".to_string(), Box::new(HumanNode));
 
-        let mut executor = DagExecutor::new(bus.clone(), exec_id.to_string());
+        let mut executor = DagExecutor::new(bus.clone(), exec_id.into());
         let sm = executor.state_machine();
 
         let run_handle = tokio::spawn(async move {
diff --git a/crates/df-workflow/src/executor_helpers.rs b/crates/df-workflow/src/executor_helpers.rs
index a567661..bdeb3ca 100644
--- a/crates/df-workflow/src/executor_helpers.rs
+++ b/crates/df-workflow/src/executor_helpers.rs
@@ -110,7 +110,7 @@ async fn node_config_overrides_global_in_node_context() {
 
     let dag = registry.build_dag(&def).expect("build_dag");
 
-    let mut executor = DagExecutor::new(EventBus::new(), "test-nodecfg".to_string());
+    let mut executor = DagExecutor::new(EventBus::new(), "test-nodecfg".into());
     // 全局 config 写 foo=GLOBAL（验证被 n1 节点级覆盖，n2 回退用全局）
     let outputs = executor
         .run(&dag, serde_json::json!({ "foo": "GLOBAL" }))
@@ -138,7 +138,7 @@ async fn test_same_layer_runs_in_parallel() {
     dag.add_node("a".to_string(), Box::new(SleepNode { sleep_ms: 100 }));
     dag.add_node("b".to_string(), Box::new(SleepNode { sleep_ms: 100 }));
 
-    let mut executor = DagExecutor::new(EventBus::new(), "test-exec".to_string());
+    let mut executor = DagExecutor::new(EventBus::new(), "test-exec".into());
     let start = std::time::Instant::now();
     let outputs = executor.run(&dag, serde_json::Value::Null).await.unwrap();
     let elapsed = start.elapsed();
@@ -161,7 +161,7 @@ async fn test_layer_failure_aborts_following_layers() {
     dag.add_node("c".to_string(), Box::new(SleepNode { sleep_ms: 10 }));
     dag.add_edge("a".to_string(), "c".to_string());
 
-    let mut executor = DagExecutor::new(EventBus::new(), "test-exec".to_string());
+    let mut executor = DagExecutor::new(EventBus::new(), "test-exec".into());
     let err = executor
         .run(&dag, serde_json::Value::Null)
         .await
@@ -206,7 +206,7 @@ async fn test_cancelled_node_skips_set_failed() {
     let mut dag = Dag::new();
     dag.add_node("x".to_string(), Box::new(CancelSelfNode));
 
-    let mut executor = DagExecutor::new(EventBus::new(), "test-cancel".to_string());
+    let mut executor = DagExecutor::new(EventBus::new(), "test-cancel".into());
     let result = executor.run(&dag, serde_json::Value::Null).await;
 
     // run 返回 Err(取消致中止后续层),但不 panic/bail transition
@@ -257,7 +257,7 @@ async fn test_cancelled_node_skips_set_completed() {
     let mut dag = Dag::new();
     dag.add_node("y".to_string(), Box::new(CancelSelfThenOkNode));
 
-    let mut executor = DagExecutor::new(EventBus::new(), "test-cancel-ok".to_string());
+    let mut executor = DagExecutor::new(EventBus::new(), "test-cancel-ok".into());
     let result = executor.run(&dag, serde_json::Value::Null).await;
 
     // run 返回 Ok —— Ok 节点不应因 TOCTOU 取消被误判为失败
@@ -285,7 +285,7 @@ async fn test_cancelled_node_emits_node_cancelled_event() {
 
     let bus = EventBus::new();
     let mut rx = bus.subscribe();
-    let mut executor = DagExecutor::new(bus, "test-cancel-event".to_string());
+    let mut executor = DagExecutor::new(bus, "test-cancel-event".into());
     let _ = executor.run(&dag, serde_json::Value::Null).await;
 
     // 收集所有事件(run 已结束,事件总线无新事件)
@@ -408,7 +408,7 @@ async fn conditions_eval_routes_by_edge_condition() {
         "$.ok == false".to_string(),
     );
 
-    let mut executor = DagExecutor::new(EventBus::new(), "test-cond-route".to_string());
+    let mut executor = DagExecutor::new(EventBus::new(), "test-cond-route".into());
     let outputs = executor
         .run(&dag, serde_json::Value::Null)
         .await
@@ -462,7 +462,7 @@ async fn conditions_eval_skip_keeps_pending() {
         "$.ok == false".to_string(),
     );
 
-    let mut executor = DagExecutor::new(EventBus::new(), "test-cond-skip".to_string());
+    let mut executor = DagExecutor::new(EventBus::new(), "test-cond-skip".into());
     let outputs = executor
         .run(&dag, serde_json::Value::Null)
         .await
@@ -504,7 +504,7 @@ async fn conditions_eval_unconditional_edge_always_passes() {
         "$.ok == false".to_string(),
     );
 
-    let mut executor = DagExecutor::new(EventBus::new(), "test-cond-mix".to_string());
+    let mut executor = DagExecutor::new(EventBus::new(), "test-cond-mix".into());
     let outputs = executor
         .run(&dag, serde_json::Value::Null)
         .await
diff --git a/src-tauri/src/commands/ai/audit/mod.rs b/src-tauri/src/commands/ai/audit/mod.rs
index c8278ef..dcdb895 100644
--- a/src-tauri/src/commands/ai/audit/mod.rs
+++ b/src-tauri/src/commands/ai/audit/mod.rs
@@ -485,6 +485,7 @@ pub(crate) async fn process_tool_calls(
 #[cfg(test)]
 mod tests {
     use super::*;
+    use super::path_auth::extract_file_tool_paths;
 
     /// grep 走单路径授权申请路径（NeedsAuth），非 search_files 盲拒（Denied）。
     ///
diff --git a/src-tauri/src/commands/ai/augmentation/inject.rs b/src-tauri/src/commands/ai/augmentation/inject.rs
index 64ee54d..fda0bef 100644
--- a/src-tauri/src/commands/ai/augmentation/inject.rs
+++ b/src-tauri/src/commands/ai/augmentation/inject.rs
@@ -189,6 +189,7 @@ mod tests {
             status: ProjectStatus::InProgress,
             description: "AI-native dev tool".into(),
             path: Some(SanitizedPath::new("E:/wk-lab/devflow")),
+            extra: vec![],
         };
         let seg = build_augmentation_segment(&[aug], "zh");
         assert!(seg.starts_with("--- 以下是用户选择的上下文参考"), "头部应隔离标注, got: {}", seg);
@@ -206,6 +207,7 @@ mod tests {
             status: TaskStatus::Todo,
             description: "do X".into(),
             project_name: Some("devflow".into()),
+            extra: vec![],
         };
         let seg = build_augmentation_segment(&[aug], "zh");
         assert!(seg.contains("【任务】Implement X"));
@@ -234,6 +236,7 @@ mod tests {
                 title: "Idea1".into(),
                 status: IdeaStatus::Approved,
                 description: String::new(),
+                extra: vec![],
             },
             Augmentation::Project {
                 id: "p1".into(),
@@ -241,6 +244,7 @@ mod tests {
                 status: ProjectStatus::Planning,
                 description: String::new(),
                 path: None,
+                extra: vec![],
             },
         ];
         let seg = build_augmentation_segment(&augs, "zh");
@@ -258,6 +262,7 @@ mod tests {
             title: "Idea1".into(),
             status: IdeaStatus::Approved,
             description: String::new(),
+            extra: vec![],
         };
         let seg = build_augmentation_segment(&[aug], "en");
         assert!(seg.starts_with("--- The following is the context"), "en 头部: {}", seg);
@@ -271,6 +276,7 @@ mod tests {
             title: "Idea1".into(),
             status: IdeaStatus::Approved,
             description: String::new(),
+            extra: vec![],
         };
         let seg = build_augmentation_segment(&[aug], "fr");
         assert!(seg.starts_with("--- 以下是用户选择的上下文参考"), "未知 lang 应按 zh 兜底");
@@ -284,6 +290,7 @@ mod tests {
             status: ProjectStatus::Planning,
             description: String::new(),
             path: None,
+            extra: vec![],
         };
         let seg = build_augmentation_segment(&[aug], "zh");
         assert!(!seg.contains("目录:"), "无 path 不应渲染目录行: {}", seg);
diff --git a/src-tauri/src/commands/ai/commands/conversation.rs b/src-tauri/src/commands/ai/commands/conversation.rs
index 1db60d4..d4d5173 100644
--- a/src-tauri/src/commands/ai/commands/conversation.rs
+++ b/src-tauri/src/commands/ai/commands/conversation.rs
@@ -637,7 +637,7 @@ pub async fn ai_conversation_export(
 #[cfg(test)]
 mod tests {
     use super::*;
-    use df_ai::provider::{ChatMessage, ContentPart, MessageRole, MessageStatus, ToolCall, ToolCallFunction, ToolType};
+    use df_ai::provider::{ChatMessage, ContentPart, MessageRole, MessageStatus, ToolCall, ToolCallFunction};
 
     fn base_msg() -> ChatMessage {
         ChatMessage {
@@ -821,7 +821,7 @@ mod tests {
             serde_json::to_string(&msg.tool_calls).unwrap()
         );
         assert_eq!(back.model.as_deref(), Some("m"));
-        assert_eq!(back.status.as_deref(), Some("compressed"));
+        assert_eq!(back.status.as_ref(), Some(&MessageStatus::Compressed));
         assert_eq!(back.reasoning_content.as_deref(), Some("r"));
         assert_eq!(back.timestamp, Some(123));
     }
@@ -875,7 +875,7 @@ mod tests {
                             },
                         }]),
                         status: if i % 6 == 0 {
-                            Some("compressed".into())
+                            Some(MessageStatus::Compressed)
                         } else {
                             None
                         },
@@ -980,7 +980,7 @@ mod tests {
                 id: Some("m_summary".into()),
                 role: MessageRole::Assistant,
                 content: "压缩摘要".into(),
-                status: Some("compressed".into()),
+                status: Some(MessageStatus::Compressed),
                 ..base_msg()
             },
             ChatMessage {
diff --git a/src-tauri/src/commands/ai/tool_registry.rs b/src-tauri/src/commands/ai/tool_registry.rs
index b2557e2..1b6c8ee 100644
--- a/src-tauri/src/commands/ai/tool_registry.rs
+++ b/src-tauri/src/commands/ai/tool_registry.rs
@@ -4081,7 +4081,7 @@ mod tests {
             id: "proj-svc-1".to_string(),
             name: "proj-svc-1".to_string(),
             description: String::new(),
-            status: "planning".to_string(),
+            status: ProjectStatus::Planning,
             idea_id: None,
             path: None,
             stack: None,
diff --git a/src/components/AiChat.vue b/src/components/AiChat.vue
index d6f33ef..0faad00 100644
--- a/src/components/AiChat.vue
+++ b/src/components/AiChat.vue
@@ -128,7 +128,7 @@
 </template>
 
 <script setup lang="ts">
-import { ref, reactive, computed, nextTick, onMounted, onBeforeUnmount, watch } from 'vue'
+import { ref, computed, nextTick, onMounted, onBeforeUnmount, watch } from 'vue'
 import { useI18n } from 'vue-i18n'
 import { useRouter } from 'vue-router'
 import { listen } from '@tauri-apps/api/event'
@@ -143,6 +143,7 @@ import MaxRoundsCard from './ai/MaxRoundsCard.vue'
 import HelpRequiredCard from './ai/HelpRequiredCard.vue'
 import DirAuthDialog from './ai/DirAuthDialog.vue'
 import { useConfirm } from '../composables/useConfirm'
+import { useToast } from '../composables/useToast'
 import { useProjectStore } from '../stores/project'
 import type { AiMessage } from '../api/types'
 
@@ -177,18 +178,10 @@ function sendExamplePrompt(i18nKey: string) {
   chatInputRef.value?.sendExamplePrompt(i18nKey)
 }
 
-// ── 错误 toast(零依赖,复用 Settings.vue 同款 reactive toast) ──
+// ── 错误 toast(useToast composable,消除 AiChat/Settings/Projects/TaskDetail 4 处重复) ──
 // AiChat 可能以分离窗口运行(App.vue 根 toast 不在 DOM 中),故本组件自管一个 toast;
 // i18n 不在本任务白名单,文案硬编码,后续补 aiChat.toastSendFail key
-const toast = reactive({ visible: false, msg: '', type: 'error' as 'error' | 'warning' | 'info' })
-let _toastTimer: ReturnType<typeof setTimeout> | null = null
-function showToast(msg: string, type: 'error' | 'warning' | 'info' = 'info') {
-  toast.msg = msg
-  toast.type = type
-  toast.visible = true
-  if (_toastTimer) clearTimeout(_toastTimer)
-  _toastTimer = setTimeout(() => { toast.visible = false }, 3000)
-}
+const { toast, showToast } = useToast()
 
 // B-260616-12: 工具慢执行提示事件 unlistener(onMounted 注册,onBeforeUnmount 释放)
 let _unlistenToolSlow: (() => void) | null = null
@@ -460,7 +453,7 @@ onBeforeUnmount(() => {
   store.stopContextListener()
   if (_unlistenToolSlow) { _unlistenToolSlow(); _unlistenToolSlow = null } // B-260616-12
   if (_unlistenAutoApproved) { _unlistenAutoApproved(); _unlistenAutoApproved = null } // AE-2025-04
-  if (_toastTimer) { clearTimeout(_toastTimer); _toastTimer = null }
+  // toast timer 清理由 useToast composable 的 onUnmounted 自动管理
 })
 
 onMounted(async () => {
diff --git a/src/components/ai/ConversationSidebar.vue b/src/components/ai/ConversationSidebar.vue
index 741560a..94b81d0 100644
--- a/src/components/ai/ConversationSidebar.vue
+++ b/src/components/ai/ConversationSidebar.vue
@@ -50,7 +50,7 @@
                 {{ conv.title || t('aiChat.newConversation') }}
                 <span v-if="store.isGenerating(conv.id)" class="ai-conv-gen-dot" :title="t('aiChat.generating')"></span>
               </span>
-              <span class="ai-conv-item-time">{{ formatTime(conv.updated_at) }}</span>
+              <span class="ai-conv-item-time">{{ formatRelative(conv.updated_at) }}</span>
             </div>
             <div class="ai-conv-item-actions">
               <div class="ai-conv-item-more">
@@ -132,7 +132,7 @@
                   <!-- F-09: 多会话并发生成指示器(后台/当前会话生成中均显脉冲点,多会话可同时显示) -->
                   <span v-if="store.isGenerating(conv.id)" class="ai-conv-gen-dot" :title="t('aiChat.generating')"></span>
                 </span>
-                <span class="ai-conv-item-time">{{ formatTime(conv.updated_at) }}</span>
+                <span class="ai-conv-item-time">{{ formatRelative(conv.updated_at) }}</span>
               </div>
               <div class="ai-conv-item-actions">
                 <div class="ai-conv-item-more">
@@ -177,7 +177,7 @@
                   {{ conv.title || t('aiChat.newConversation') }}
                   <span v-if="store.isGenerating(conv.id)" class="ai-conv-gen-dot" :title="t('aiChat.generating')"></span>
                 </span>
-                <span class="ai-conv-item-time">{{ formatTime(conv.updated_at) }}</span>
+                <span class="ai-conv-item-time">{{ formatRelative(conv.updated_at) }}</span>
               </div>
               <div class="ai-conv-item-actions">
                 <div class="ai-conv-item-more">
@@ -328,10 +328,6 @@ function onSelectSearchResult(id: string) {
   store.state.searchQuery = ''
 }
 
-function formatTime(ts: string): string {
-  return formatRelative(ts)
-}
-
 // ── 对话分组:今天 / 昨天 / 更早 ──
 const bucketLabels = computed<Record<string, string>>(() => ({
   today: t('aiChat.today'),
diff --git a/src/components/project/FilePreview.vue b/src/components/project/FilePreview.vue
index 2ee3bb3..90228a1 100644
--- a/src/components/project/FilePreview.vue
+++ b/src/components/project/FilePreview.vue
@@ -91,6 +91,7 @@ import { ref, watch, computed, onUnmounted } from 'vue'
 import { moduleApi } from '@/api/module'
 import hljs from 'highlight.js/lib/common'
 import { useMarkdown, useRendered } from '@/composables/useMarkdown'
+import { escapeHtml } from '@/utils/html'
 
 const props = defineProps<{
   moduleId: string
@@ -284,10 +285,6 @@ async function loadFile() {
   }
 }
 
-function escapeHtml(s: string): string {
-  return s.replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;')
-}
-
 function joinPath(root: string, rel: string): string {
   const sep = root.includes('\\') ? '\\' : '/'
   const normRel = rel.split('/').join(sep)
diff --git a/src/components/project/ModuleNode.vue b/src/components/project/ModuleNode.vue
index 69eb0f1..a9b8a92 100644
--- a/src/components/project/ModuleNode.vue
+++ b/src/components/project/ModuleNode.vue
@@ -4,7 +4,7 @@
       <span class="module-node__icon">📦</span>
       <span class="module-node__name">{{ data.name }}</span>
     </div>
-    <div class="module-node__path">{{ shortPath }}</div>
+    <div class="module-node__path">{{ truncatedPath }}</div>
     <div v-if="stackList.length" class="module-node__tags">
       <span v-for="s in stackList" :key="s" class="module-node__tag">{{ s }}</span>
     </div>
@@ -13,6 +13,7 @@
 
 <script setup lang="ts">
 import { computed } from 'vue'
+import { parseJsonArray } from '@/utils/json'
 
 const props = defineProps<{
   data: {
@@ -24,21 +25,13 @@ const props = defineProps<{
   selected?: boolean
 }>()
 
-const shortPath = computed(() => {
+const truncatedPath = computed(() => {
   const p = props.data?.path || ''
   if (p.length <= 32) return p
   return '...' + p.slice(-29)
 })
 
-const stackList = computed(() => {
-  if (!props.data?.stack) return []
-  try {
-    const parsed = JSON.parse(props.data.stack)
-    return Array.isArray(parsed) ? parsed.slice(0, 3) : []
-  } catch {
-    return []
-  }
-})
+const stackList = computed(() => parseJsonArray(props.data?.stack).slice(0, 3))
 </script>
 
 <style scoped>
diff --git a/src/composables/useMarkdown.ts b/src/composables/useMarkdown.ts
index 5473795..2aed899 100644
--- a/src/composables/useMarkdown.ts
+++ b/src/composables/useMarkdown.ts
@@ -166,9 +166,7 @@ export function useRendered(getText: () => string): {
   return { rendered, ensureLoaded }
 }
 
-function escapeHtml(text: string): string {
-  return text.replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;')
-}
+import { escapeHtml } from '@/utils/html'
 
 /// marked 未就绪时的兜底渲染:HTML 转义 + 换行转 <br>(纯文本安全降级)
 function escapeFallback(text: string): string {
@@ -217,7 +215,7 @@ const _DIFF_LINE_RE = /^[ \t]*[+-][^\n]*$/ // 行首可选空格/tab + +/- + 任
 const _PLUS_LINE_RE = /^[ \t]*\+[^\n]*$/ // 含 + 的行(+ 必须含的判定)
 const _FENCE_OPEN_RE = /^[ \t]{0,3}(```|~~~)/ // marked 围栏开头(行首 ≤3 空格 + 3+ 反引号/波浪)
 
-export function wrapNakedDiff(text: string): string {
+function wrapNakedDiff(text: string): string {
   if (!text) return text
   // 快速短路:全文无 +/- 行首特征直接返回原文(避免大文本白跑切段)
   if (!/[+-]/.test(text)) return text
diff --git a/src/composables/useStoreAction.ts b/src/composables/useStoreAction.ts
index 9f28fcb..94d2a07 100644
--- a/src/composables/useStoreAction.ts
+++ b/src/composables/useStoreAction.ts
@@ -12,10 +12,10 @@
  * 注:带 seq 竞态守卫的场景调用方需在 fn 内部判断，不在本工具职责范围。
  */
 
-import type { Ref } from 'vue'
+// (Ref import 已移除,_Unused 类型已删除)
 
-/** 带 error 字段的 store state 形状（仅约束 error，其他字段任意）。 */
-export interface ErrorSink {
+/** 带 error 字段的 store state 形状（仅约束 error，其他字段任意）。仅本模块内部使用。 */
+interface ErrorSink {
   error: string | null
 }
 
@@ -40,12 +40,8 @@ export async function runWithCatch<T>(
   }
 }
 
-/**
- * 把 unknown 错误转为可读字符串（无则返 undefined，由调用方兜底 i18n）。
- *
- * Tauri invoke 抛出的通常是 string 或 Error 实例。
- */
-export function stringifyError(e: unknown): string | undefined {
+// stringifyError 仅本模块内部使用(runWithCatch/runWithCatchGuarded 调用),不导出。
+function stringifyError(e: unknown): string | undefined {
   if (typeof e === 'string') return e
   if (e instanceof Error) return e.message || e.toString()
   if (e && typeof e === 'object' && 'toString' in e) {
@@ -81,5 +77,4 @@ export async function runWithCatchGuarded<T>(
   }
 }
 
-// 显式标记 Ref 未使用（避免未来用上时改导入）
-export type _Unused = Ref<unknown>
+// _Unused 类型从未被外部 import,已删除(同时移除上方 Ref import)。
diff --git a/src/composables/useToast.ts b/src/composables/useToast.ts
new file mode 100644
index 0000000..fc71773
--- /dev/null
+++ b/src/composables/useToast.ts
@@ -0,0 +1,59 @@
+/**
+ * 轻量 toast 提示 composable — 消除 AiChat / Settings / Projects / TaskDetail 4 处重复。
+ *
+ * 原 4 处各自 reactive/ref + _toastTimer + showToast + onUnmounted 清理,
+ * 且 Projects 用 4000ms 其余 3000ms(体验不一致 bug)。
+ * 本 composable 统一默认 3000ms,支持调用方按需传 durationMs。
+ *
+ * 用法:
+ *   const { toast, showToast } = useToast()
+ *   showToast('保存成功')
+ *   showToast('导入失败', 'error', 4000)
+ *   // template: <div v-if="toast.visible" class="toast ...">{{ toast.msg }}</div>
+ */
+import { reactive, onUnmounted } from 'vue'
+
+export type ToastType = 'info' | 'error' | 'warning'
+
+export interface ToastState {
+  visible: boolean
+  msg: string
+  type: ToastType
+}
+
+let _timer: ReturnType<typeof setTimeout> | null = null
+
+export function useToast(defaultDurationMs = 3000) {
+  const toast = reactive<ToastState>({
+    visible: false,
+    msg: '',
+    type: 'info',
+  })
+
+  function showToast(msg: string, type: ToastType = 'info', durationMs?: number) {
+    toast.msg = msg
+    toast.type = type
+    toast.visible = true
+    if (_timer) clearTimeout(_timer)
+    _timer = setTimeout(() => {
+      toast.visible = false
+    }, durationMs ?? defaultDurationMs)
+  }
+
+  function hideToast() {
+    if (_timer) {
+      clearTimeout(_timer)
+      _timer = null
+    }
+    toast.visible = false
+  }
+
+  onUnmounted(() => {
+    if (_timer) {
+      clearTimeout(_timer)
+      _timer = null
+    }
+  })
+
+  return { toast, showToast, hideToast }
+}
diff --git a/src/stores/knowledge.ts b/src/stores/knowledge.ts
index c15af5a..8b6e7c0 100644
--- a/src/stores/knowledge.ts
+++ b/src/stores/knowledge.ts
@@ -2,6 +2,7 @@ import { reactive, computed } from 'vue'
 import { knowledgeApi } from '@/api'
 import { t } from '@/i18n/i18n-helpers'
 import { runWithCatch, runWithCatchGuarded } from '@/composables/useStoreAction'
+import { parseJsonArray } from '@/utils/json'
 import type {
   KnowledgeRecord,
   KnowledgeDetailPayload,
@@ -46,14 +47,8 @@ export const KNOWLEDGE_KINDS = [
 ] as const
 
 /** 解析 tags JSON 字符串为 string[] */
-export function parseTags(tags: string | null): string[] {
-  if (!tags) return []
-  try {
-    const arr = JSON.parse(tags)
-    return Array.isArray(arr) ? arr : []
-  } catch {
-    return []
-  }
+export function parseTags(tags: string | null | undefined): string[] {
+  return parseJsonArray(tags)
 }
 
 // ── 知识 label 文案辅助(列表 Knowledge.vue 与详情 KnowledgeDetail.vue 共用) ──
diff --git a/src/utils/html.ts b/src/utils/html.ts
new file mode 100644
index 0000000..eb79391
--- /dev/null
+++ b/src/utils/html.ts
@@ -0,0 +1,8 @@
+/**
+ * HTML 转义 — 消除 useMarkdown / FilePreview 两处重复实现。
+ */
+
+/** 转义 &, <, > 三个核心 HTML 特殊字符 */
+export function escapeHtml(s: string): string {
+  return s.replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;')
+}
diff --git a/src/utils/json.ts b/src/utils/json.ts
new file mode 100644
index 0000000..15cb62c
--- /dev/null
+++ b/src/utils/json.ts
@@ -0,0 +1,23 @@
+/**
+ * JSON 字符串数组解析 — 消除 parseStack / parseTags / ModuleNode 内联 3 处重复。
+ *
+ * 后端将 string[] 以 JSON.stringify 形式存于 stack/tags 等字段;
+ * 解析失败或非数组时返回空数组,避免渲染崩溃。
+ */
+
+/**
+ * 安全解析 JSON 字符串数组。
+ * null / 空 / 非法 JSON / 非数组 → 返回 fallback(默认 [])。
+ */
+export function parseJsonArray<T = string>(
+  raw: string | null | undefined,
+  fallback: T[] = [],
+): T[] {
+  if (!raw) return fallback
+  try {
+    const arr = JSON.parse(raw)
+    return Array.isArray(arr) ? arr : fallback
+  } catch {
+    return fallback
+  }
+}
diff --git a/src/utils/project.ts b/src/utils/project.ts
index d8659fa..3ee942a 100644
--- a/src/utils/project.ts
+++ b/src/utils/project.ts
@@ -3,6 +3,8 @@
 //! parseStack 此前在 Projects.vue 与 ProjectDetail.vue 各有一份重复实现，
 //! 现抽到此处统一维护。
 
+import { parseJsonArray } from './json'
+
 /**
  * 解析技术栈 JSON 数组字符串（防崩）。
  *
@@ -10,11 +12,5 @@
  * 解析失败或非数组时返回空数组，避免渲染崩溃。
  */
 export function parseStack(stack: string | null | undefined): string[] {
-  if (!stack) return []
-  try {
-    const arr = JSON.parse(stack)
-    return Array.isArray(arr) ? arr : []
-  } catch {
-    return []
-  }
+  return parseJsonArray(stack)
 }
diff --git a/src/utils/time.ts b/src/utils/time.ts
index 8dbc253..5fec6bf 100644
--- a/src/utils/time.ts
+++ b/src/utils/time.ts
@@ -16,8 +16,8 @@ import { t, currentLocale } from '@/i18n/i18n-helpers'
 // CR-260615-08(P1-10):相对时间走 i18n(原硬编码中文,en locale 时间恒中文)。
 // 类型安全访问经 i18n-helpers 收口(规避 vue-i18n TS2589)。
 
-/** 解析任意时间值为毫秒时间戳；无效或空返回 null */
-export function parseTs(v: string | number | null | undefined): number | null {
+/** 解析任意时间值为毫秒时间戳；无效或空返回 null(仅本模块内部使用) */
+function parseTs(v: string | number | null | undefined): number | null {
   if (v == null) return null
   if (typeof v === 'number') {
     if (!Number.isFinite(v)) return null
diff --git a/src/views/ProjectDetail.vue b/src/views/ProjectDetail.vue
index 4677155..d904963 100644
--- a/src/views/ProjectDetail.vue
+++ b/src/views/ProjectDetail.vue
@@ -188,7 +188,7 @@
                   <div class="score-bar-track">
                     <div
                       class="score-bar-fill"
-                      :class="dim.score >= 80 ? 'fill-high' : dim.score >= 60 ? 'fill-mid' : 'fill-low'"
+                      :class="'fill-' + scoreTier(dim.score)"
                       :style="{ width: dim.score + '%' }"
                     ></div>
                   </div>
@@ -276,7 +276,7 @@ import { useProjectStore } from '@/stores/project'
 import { projectApi } from '@/api'
 import { formatDate } from '@/utils/time'
 import { parseStack } from '@/utils/project'
-import { parseScores as parseScoresJson, assessmentClass, assessmentLabel as assessmentLabelI18n } from '@/utils/ideaEval'
+import { parseScores as parseScoresJson, assessmentClass, assessmentLabel as assessmentLabelI18n, scoreTier } from '@/utils/ideaEval'
 import { projectStatusLabel, taskStatusLabel, taskStatusClass } from '../constants/project'
 import ConfirmDialog from '@/components/ConfirmDialog.vue'
 import ApprovalDialog from '@/components/project/ApprovalDialog.vue'
diff --git a/src/views/Projects.vue b/src/views/Projects.vue
index c564398..91013a4 100644
--- a/src/views/Projects.vue
+++ b/src/views/Projects.vue
@@ -164,7 +164,7 @@
 </template>
 
 <script setup lang="ts">
-import { ref, computed, onMounted, onUnmounted } from 'vue'
+import { ref, computed, onMounted } from 'vue'
 import { useI18n } from 'vue-i18n'
 import { open } from '@tauri-apps/plugin-dialog'
 import { useProjectStore } from '@/stores/project'
@@ -174,6 +174,7 @@ import ConfirmDialog from '@/components/ConfirmDialog.vue'
 import ProjectCard from '@/components/project/ProjectCard.vue'
 import Paginator from '@/components/Paginator.vue'
 import { useConfirm } from '@/composables/useConfirm'
+import { useToast } from '@/composables/useToast'
 import type { ProjectRecord } from '@/api/types'
 import type { ScannedProjectItem } from '@/api/project'
 
@@ -303,14 +304,7 @@ onMounted(() => {
   store.loadProjects()
 })
 
-// 卸载清 toast timer:防组件已离开视图后 4s 内 timer 触发向已销毁组件写状态。
-// 对齐 Settings.vue 的 _toastTimer 清理模式(Knowledge.vue searchTimer 同模式)。
-onUnmounted(() => {
-  if (_toastTimer) {
-    clearTimeout(_toastTimer)
-    _toastTimer = null
-  }
-})
+// toast timer 清理由 useToast composable 的 onUnmounted 自动管理
 
 // ── 导入历史项目(F-260614-06 scan 第二步) ──
 const showImportModal = ref(false)
@@ -320,14 +314,7 @@ const importScanning = ref(false)
 const importError = ref('')
 const importRunning = ref(false)
 const selectedImportPaths = ref<Set<string>>(new Set())
-const toast = ref({ visible: false, msg: '', type: 'info' as 'info' | 'error' })
-let _toastTimer: ReturnType<typeof setTimeout> | null = null
-
-function showToast(msg: string, type: 'info' | 'error' = 'info') {
-  toast.value = { visible: true, msg, type }
-  if (_toastTimer) clearTimeout(_toastTimer)
-  _toastTimer = setTimeout(() => { toast.value.visible = false }, 4000)
-}
+const { toast, showToast } = useToast(4000)  // Projects 导入操作 toast 用 4000ms(操作类提示)
 
 const allImportSelected = computed(() =>
   scannedItems.value.length > 0
diff --git a/src/views/Settings.vue b/src/views/Settings.vue
index 3affced..9ebf8ab 100644
--- a/src/views/Settings.vue
+++ b/src/views/Settings.vue
@@ -67,8 +67,9 @@
 </template>
 
 <script setup lang="ts">
-import { computed, reactive, ref, shallowRef, onMounted, onUnmounted, nextTick } from 'vue'
+import { computed, ref, shallowRef, onMounted, onUnmounted, nextTick } from 'vue'
 import { useConfirm } from '@/composables/useConfirm'
+import { useToast } from '@/composables/useToast'
 import ConfirmDialog from '@/components/ConfirmDialog.vue'
 import SettingsNav, { type SettingsCategory } from '@/components/settings/SettingsNav.vue'
 import ProviderPanel from '@/components/settings/ProviderPanel.vue'
@@ -90,17 +91,8 @@ import { t as ti18n } from '@/i18n/i18n-helpers'
 // (阶段3 UX 重构:左导航 + 右按 activeCategory 渲染,各功能域 state/methods 已拆到子组件)
 // ============================================================
 
-// 顶部轻量提示（错误/警告/完成），3s 自动消失；零依赖，替代未接入的 Arco Message
-const toast = reactive({ visible: false, msg: '', type: 'info' as 'error' | 'warning' | 'info' })
-let _toastTimer: ReturnType<typeof setTimeout> | null = null
-
-function showToast(msg: string, type: 'error' | 'warning' | 'info' = 'info') {
-  toast.msg = msg
-  toast.type = type
-  toast.visible = true
-  if (_toastTimer) clearTimeout(_toastTimer)
-  _toastTimer = setTimeout(() => { toast.visible = false }, 3000)
-}
+// 顶部轻量提示(useToast composable,消除 4 处重复;默认 3000ms)
+const { toast, showToast } = useToast()
 
 // 确认弹层状态机抽至 composables/useConfirm(原 4 视图重复:Projects/ProjectDetail/Ideas/Settings)
 // 模板 confirmState.visible/msg 在 <script setup> 中自动解包 ref,沿用既有内联确认弹层
@@ -207,9 +199,8 @@ onMounted(() => {
   void loadAiProviders()
 })
 
-// 组件卸载清 toast/resize timer;各子面板自管自身 debounce timer(各自 onUnmounted)
+// 组件卸载清 resize timer;toast 清理由 useToast 自动管理;各子面板自管自身 debounce timer
 onUnmounted(() => {
-  if (_toastTimer) clearTimeout(_toastTimer)
   if (_resizeTimer) clearTimeout(_resizeTimer)
   window.removeEventListener('resize', onResize)
   providerPanelRef.value?.clearPoolTimer()