fix(resource): 候选资源全部被过滤时显示友好提示而非 404 空态

搜索流追踪过滤前候选资源数（candidate_items 或搜索阶段 total_items），最终结果为空且存在候选时显示"找到 N 个资源，但均不符合过滤规则"。Closes #646

src/locales/en-US.ts

@@ -1416,6 +1416,7 @@ export default {
     searching: 'Searching, please wait...',
     noData: 'No Data',
     noResourceFound: 'No resources found',
+    filteredNoResults: 'Found {count} resource(s), but none match the filter rules',
     searchStreamTimeout: 'The search connection timed out. Please try again later.',
     searchStreamDisconnected: 'The search connection was interrupted. Please try again later.',
     aiRecommend: 'AI Recommendation',

src/locales/zh-CN.ts

@@ -1406,6 +1406,7 @@ export default {
     searching: '正在搜索，请稍候...',
     noData: '没有数据',
     noResourceFound: '未搜索到任何资源',
+    filteredNoResults: '找到 {count} 个资源，但均不符合过滤规则',
     searchStreamTimeout: '搜索连接长时间无响应，请稍后重试',
     searchStreamDisconnected: '搜索连接已中断，请稍后重试',
     aiRecommend: '智能推荐',

src/locales/zh-TW.ts

@@ -1404,6 +1404,7 @@ export default {
     searching: '正在搜索，請稍候...',
     noData: '沒有數據',
     noResourceFound: '未搜索到任何資源',
+    filteredNoResults: '找到 {count} 個資源，但均不符合過濾規則',
     searchStreamTimeout: '搜索連線長時間無回應，請稍後重試',
     searchStreamDisconnected: '搜索連線已中斷，請稍後重試',
     aiRecommend: '智能推薦',

src/pages/__tests__/resource.spec.ts

@@ -549,6 +549,54 @@ describe('resource page search flow', () => {
     expect(screen.queryByText('搜索服务暂不可用')).not.toBeInTheDocument()
   })
 
+  it('shows a friendly message when all candidate resources are filtered out', async () => {
+    await renderResource({
+      path: '/resource',
+      query: { keyword: '过滤空结果', result_type: 'torrent' },
+    })
+    const source = await latestEventSource()
+
+    // 搜索阶段返回候选资源，最终替换事件为空表示全部被过滤规则淘汰
+    source.message({
+      items: [createTorrent({ title: '候选资源' })],
+      stage: 'searching',
+      total_items: 19,
+      type: 'append',
+    })
+    source.message({
+      candidate_items: 19,
+      items: [],
+      stage: 'filtered',
+      total_items: 0,
+      type: 'replace',
+      value: 100,
+    })
+    source.message({ type: 'done' })
+    source.fail()
+
+    expect(await screen.findByTestId('no-data')).toHaveTextContent('找到 19 个资源，但均不符合过滤规则')
+    expect(screen.queryByText('未搜索到任何资源')).not.toBeInTheDocument()
+  })
+
+  it('shows a friendly message when the done event reports filtered candidates for title search', async () => {
+    await renderResource({
+      path: '/resource',
+      query: { keyword: '标题过滤空结果', result_type: 'torrent' },
+    })
+    const source = await latestEventSource()
+
+    // 标题搜索没有 replace 事件，候选数由 done 事件的 candidate_items 携带
+    source.message({
+      candidate_items: 5,
+      items: [],
+      total_items: 0,
+      type: 'done',
+    })
+    source.fail()
+
+    expect(await screen.findByTestId('no-data')).toHaveTextContent('找到 5 个资源，但均不符合过滤规则')
+  })
+
   it('restores the default empty-state message when the fallback request succeeds without results', async () => {
     mocks.apiGet.mockResolvedValueOnce({ data: [], success: true })
     const rendered = await renderResource({

src/pages/resource.vue

@@ -355,6 +355,9 @@ const displayResourceCount = computed(() =>
 // 搜索中只显示进度区域，避免结果抬头和进度条同时占用顶部空间。
 const showResultHeader = computed(() => isRefreshed.value && !progressActive.value)
 
+// 记录过滤前的候选资源数，用于过滤后无结果时给出友好提示
+let streamCandidateCount = 0
+
 let pendingStreamItems: Array<Context> = []
 let pendingSubtitleStreamItems: Array<SubtitleInfo> = []
 const streamReplaceBatchCollector = new SearchReplaceBatchCollector<Context>()
@@ -597,6 +600,7 @@ function resetSearchResults() {
   // 新搜索开始时先回到未完成态，避免上一轮空态在 SSE 返回前抢先显示。
   isRefreshed.value = false
   errorDescription.value = t('resource.noResourceFound')
+  streamCandidateCount = 0
   rawDataList.value = []
   rawSubtitleDataList.value = []
   originalDataList.value = []
@@ -684,11 +688,29 @@ function appendSubtitleStreamResults(items: SubtitleInfo[]) {
   scheduleStreamFlush()
 }
 
+// 更新候选资源数：优先使用后端显式给出的 candidate_items，否则取搜索阶段事件的 total_items
+function updateStreamCandidateCount(eventData: { candidate_items?: unknown; stage?: unknown; total_items?: unknown }) {
+  if (typeof eventData.candidate_items === 'number') {
+    streamCandidateCount = Math.max(streamCandidateCount, eventData.candidate_items)
+  } else if (eventData.stage === 'searching' && typeof eventData.total_items === 'number') {
+    streamCandidateCount = Math.max(streamCandidateCount, eventData.total_items)
+  }
+}
+
+// 过滤后无结果但存在候选资源时，用友好提示替代默认的“未搜索到任何资源”
+function applyFilteredEmptyResultMessage(resultCount: number) {
+  if (resultCount === 0 && streamCandidateCount > 0) {
+    errorDescription.value = t('resource.filteredNoResults', { count: streamCandidateCount })
+  }
+}
+
 // 完整最终结果到达后原子替换资源列表。
 function applyFinalStreamResults(items: Context[]) {
   streamFinalResultApplied = true
   flushBufferedStreamState()
   setStreamResults(items)
+  // 候选全部被过滤规则淘汰时给出友好提示
+  applyFilteredEmptyResultMessage(items.length)
 }
 
 // 应用最终字幕搜索结果
@@ -734,6 +756,7 @@ function handleSearchStreamMessage(eventData: { [key: string]: any }) {
       updateSearchProgress(eventData, completedItems !== null)
       if (completedItems) applyFinalSubtitleStreamResults(completedItems)
     } else {
+      updateStreamCandidateCount(eventData)
       const completedItems = streamReplaceBatchCollector.append(eventData)
       updateSearchProgress(eventData, completedItems !== null)
       if (completedItems) applyFinalStreamResults(completedItems)
@@ -759,6 +782,7 @@ function handleSearchStreamMessage(eventData: { [key: string]: any }) {
   }
 
   const items = Array.isArray(eventData.items) ? (eventData.items as Context[]) : []
+  updateStreamCandidateCount(eventData)
   if (eventData.type === 'append') {
     updateSearchProgress(eventData)
     appendStreamResults(items)
@@ -770,6 +794,10 @@ function handleSearchStreamMessage(eventData: { [key: string]: any }) {
     applyFinalStreamResults(items)
   } else {
     updateSearchProgress(eventData)
+    // 标题搜索没有 replace 事件，最终结果为空时在此给出友好提示
+    if (eventData.type === 'done' && !streamFinalResultApplied) {
+      applyFilteredEmptyResultMessage(items.length)
+    }
   }
 }