feat(knowledge): 支持文件导入沉淀知识，知识图谱可视化随主题切换

- 后端新增 /api/knowledge/ingest/file：上传 md/txt/pdf/word/ppt/excel，
  转 Markdown 后走 wiki-capture LLM 蒸馏为陈述式知识笔记，失败回退逐字草稿
- service.capture_file + 文档专用蒸馏提示词，按主题拆分 1~4 页
- 知识图谱导出 HTML 支持 ?theme=light|dark，布局稳定后冻结，
  按度数缩放节点，悬停/点击聚焦邻居
- 前端知识库页新增「导入文件」对话框与 ingestKnowledgeFile API
- 智能体问答页与简介侧边栏 UI 优化；批量人物蒸馏脚本提取正文逻辑修正

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

frontend-web/src/pages/KnowledgeBasePage.tsx

@@ -11,6 +11,7 @@ import {
   Search,
   Sparkles,
   Trash2,
+  Upload,
   X,
 } from "lucide-react";
 import { useEffect, useMemo, useState } from "react";
@@ -323,6 +324,119 @@ function BatchImportDialog({
   );
 }
 
+function ImportFileDialog({
+  open,
+  onOpenChange,
+}: {
+  open: boolean;
+  onOpenChange: (v: boolean) => void;
+}) {
+  const { ingestFile } = useKnowledgeActions();
+  const navigate = useNavigate();
+  const [file, setFile] = useState<File | null>(null);
+  const [title, setTitle] = useState("");
+  const [tags, setTags] = useState("");
+  const [model, setModel] = useState<string | null>(null);
+
+  const reset = () => {
+    setFile(null);
+    setTitle("");
+    setTags("");
+    setModel(null);
+  };
+
+  const handleImport = async () => {
+    if (!file) {
+      toast.error("请选择文件");
+      return;
+    }
+    try {
+      const result = await ingestFile.mutateAsync({
+        file,
+        opts: {
+          title: title.trim() || undefined,
+          tags: tags.trim() || undefined,
+          status: "approved",
+          model_name: model,
+        },
+      });
+      const count = result.notes?.length ?? 1;
+      if (result.llm_fallback) {
+        // The model produced nothing usable — the file was stored verbatim as a
+        // draft instead of distilled into a wiki note.
+        toast.warning(
+          `已导入 ${count} 条（大模型异常，改用规则抽取并存为草稿）`,
+        );
+      } else {
+        toast.success(`已从文件生成 ${count} 条知识`);
+      }
+      onOpenChange(false);
+      reset();
+      if (result.note?.id) {
+        navigate(`/page/workspace/knowledge/${result.note.id}`);
+      }
+    } catch (error) {
+      toast.error(error instanceof Error ? error.message : "文件导入失败");
+    }
+  };
+
+  return (
+    <Dialog open={open} onOpenChange={onOpenChange}>
+      <DialogContent className="max-w-md">
+        <DialogHeader>
+          <DialogTitle>导入文件生成 Wiki</DialogTitle>
+          <DialogDescription>
+            上传文档（Markdown / TXT / PDF / Word / PPT / Excel），自动提炼为知识库 wiki 词条并写入 vault。
+          </DialogDescription>
+        </DialogHeader>
+        <div className="flex flex-col gap-4">
+          <label className="flex flex-col gap-1.5 text-sm">
+            选择文件
+            <Input
+              type="file"
+              accept=".md,.markdown,.txt,.pdf,.doc,.docx,.ppt,.pptx,.xls,.xlsx"
+              onChange={(e) => setFile(e.target.files?.[0] ?? null)}
+              className="cursor-pointer"
+            />
+            {file ? (
+              <span className="text-muted-foreground truncate text-xs">
+                {file.name} · {(file.size / 1024).toFixed(0)} KB
+              </span>
+            ) : null}
+          </label>
+          <Input
+            placeholder="标题（可选，留空则由模型生成）"
+            value={title}
+            onChange={(e) => setTitle(e.target.value)}
+          />
+          <Input
+            placeholder="标签，逗号分隔（可选）"
+            value={tags}
+            onChange={(e) => setTags(e.target.value)}
+          />
+          <label className="flex items-center justify-between gap-2 text-sm">
+            提炼大模型
+            <ModelNameSelect
+              value={model}
+              onChange={setModel}
+              disabled={ingestFile.isPending}
+              triggerClassName="h-9 w-[11rem]"
+            />
+          </label>
+        </div>
+        <DialogFooter>
+          <Button variant="outline" onClick={() => onOpenChange(false)}>
+            取消
+          </Button>
+          <Button onClick={() => void handleImport()} disabled={ingestFile.isPending || !file}>
+            {ingestFile.isPending ? "导入中..." : "导入并生成"}
+          </Button>
+        </DialogFooter>
+      </DialogContent>
+    </Dialog>
+  );
+}
+
 function DedupDialog({
   open,
   onOpenChange,
@@ -698,6 +812,7 @@ export default function KnowledgeBasePage() {
   const [status, setStatus] = useState("all");
   const [createOpen, setCreateOpen] = useState(false);
   const [batchOpen, setBatchOpen] = useState(false);
+  const [importOpen, setImportOpen] = useState(false);
   const [dedupOpen, setDedupOpen] = useState(false);
 
   const params = useMemo(
@@ -752,6 +867,9 @@ export default function KnowledgeBasePage() {
           </SelectContent>
         </Select>
         <div className="ml-auto flex items-center gap-2">
+          <Button variant="outline" size="sm" onClick={() => setImportOpen(true)}>
+            <Upload className="size-4" /> 导入文件
+          </Button>
           <Button variant="outline" size="sm" onClick={() => setBatchOpen(true)}>
             <RefreshCw className="size-4" /> 批量导入
           </Button>
@@ -814,6 +932,7 @@ export default function KnowledgeBasePage() {
       </div>
 
       <CreateNoteDialog open={createOpen} onOpenChange={setCreateOpen} />
+      <ImportFileDialog open={importOpen} onOpenChange={setImportOpen} />
       <BatchImportDialog open={batchOpen} onOpenChange={setBatchOpen} />
       <DedupDialog open={dedupOpen} onOpenChange={setDedupOpen} />
     </div>