diff --git a/README.md b/README.md
index 6c0d198..ac1e066 100644
--- a/README.md
+++ b/README.md
@@ -35,11 +35,15 @@ docs                 架构与工作流设计
 
 ## 当前垂直切片
 
-- 显示样例户型与图层开关。
+- 从网页真实上传 25 MB 以内的 PDF，并把原文件与首页预览保存到 MinIO。
+- 判断矢量 PDF / 扫描 PDF，统计矢量元素，并检测同页中的多个候选平面区域。
+- 在图纸上直接选择目标户型，选择结果与工作流修订号持久化到 PostgreSQL。
 - 展示从导入、清洗、白模到风格方向和多轮修改的阶段状态。
 - 提供结构化 Style DNA 面板。
 - 提供可验证的工作流状态机和命令接口。
 - 预留 MinIO、百度 OCR、GPU Worker 和多模型路由适配器。
 - 提供分类设置中心、可扩展模型池、逐模型测试、模型路由和工作流就绪门禁。
 
+当前图纸解析先处理 PDF 首页并完成“导入图纸 → 选择户型 → 进入结构确认”的真实闭环。墙、门窗、尺寸比例和房间多边形的语义分离属于下一阶段。
+
 详见 [架构设计](docs/architecture.md)、[工作流定义](docs/workflow.md) 与 [系统设置](docs/settings.md)。
diff --git a/apps/web/app/globals.css b/apps/web/app/globals.css
index 44cf21a..618404c 100644
--- a/apps/web/app/globals.css
+++ b/apps/web/app/globals.css
@@ -434,6 +434,7 @@ textarea:focus-visible,
   display: grid;
   grid-template-rows: auto minmax(0, 1fr) auto;
   gap: 12px;
+  overflow: auto;
 }
 
 .canvas-labels,
@@ -465,6 +466,156 @@ textarea:focus-visible,
   filter: contrast(1.02) saturate(0.72);
 }
 
+.plan-upload-empty {
+  min-height: 486px;
+  padding: 40px;
+  display: grid;
+  place-content: center;
+  justify-items: center;
+  gap: 14px;
+  text-align: center;
+  background:
+    radial-gradient(circle at 50% 30%, color-mix(in srgb, var(--accent) 10%, transparent), transparent 38%),
+    var(--surface-muted);
+}
+
+.plan-upload-empty h2 {
+  font-size: 20px;
+  letter-spacing: -0.025em;
+}
+
+.plan-upload-empty > p {
+  max-width: 530px;
+  color: var(--text-soft);
+  font-size: 12px;
+  line-height: 1.8;
+}
+
+.upload-emblem {
+  width: 62px;
+  height: 62px;
+  display: grid;
+  place-items: center;
+  color: var(--accent-strong);
+  border: 1px solid color-mix(in srgb, var(--accent) 32%, var(--line));
+  border-radius: 18px;
+  background: color-mix(in srgb, var(--accent) 9%, var(--surface-raised));
+  box-shadow: var(--shadow);
+}
+
+.plan-document-frame {
+  position: relative;
+  width: min(100%, 720px);
+  margin: 0 auto;
+  align-self: start;
+  overflow: hidden;
+  border: 1px solid var(--line-strong);
+  border-radius: var(--radius-surface);
+  background: #fff;
+  box-shadow: var(--shadow);
+}
+
+.plan-document-image {
+  display: block;
+  width: 100%;
+  height: auto;
+  filter: contrast(1.02) saturate(0.75);
+}
+
+.region-layer {
+  position: absolute;
+  inset: 0;
+}
+
+.detected-region {
+  position: absolute;
+  min-width: 0;
+  min-height: 0;
+  padding: 8px;
+  display: flex;
+  align-items: flex-start;
+  gap: 6px;
+  color: var(--accent-strong);
+  border: 2px solid color-mix(in srgb, var(--accent) 72%, transparent);
+  border-radius: 8px;
+  background: color-mix(in srgb, var(--accent) 8%, transparent);
+  box-shadow: inset 0 0 0 1px rgb(255 255 255 / 0.48);
+  text-align: left;
+}
+
+.detected-region > span {
+  width: 22px;
+  height: 22px;
+  flex: 0 0 22px;
+  display: grid;
+  place-items: center;
+  color: white;
+  border-radius: 50%;
+  background: var(--accent-strong);
+  font-size: 10px;
+  font-weight: 750;
+}
+
+.detected-region strong,
+.detected-region small {
+  padding: 4px 6px;
+  border-radius: 5px;
+  background: rgb(255 255 255 / 0.9);
+  font-size: 10px;
+  line-height: 1.2;
+}
+
+.detected-region small {
+  margin-left: auto;
+  color: var(--text-soft);
+}
+
+.detected-region:hover,
+.detected-region.recommended {
+  background: color-mix(in srgb, var(--accent) 14%, transparent);
+}
+
+.detected-region.selected {
+  border-color: var(--accent-strong);
+  background: color-mix(in srgb, var(--accent) 20%, transparent);
+}
+
+.detected-region:disabled {
+  cursor: default;
+  opacity: 0.78;
+}
+
+.ingestion-facts {
+  margin-top: 12px;
+  display: grid;
+  gap: 8px;
+  color: var(--text-soft);
+  font-size: 10px;
+}
+
+.ingestion-facts span,
+.workflow-error {
+  display: flex;
+  align-items: center;
+  gap: 6px;
+}
+
+.workflow-error {
+  color: var(--warning) !important;
+  font-size: 11px !important;
+}
+
+.visually-hidden {
+  position: absolute !important;
+  width: 1px !important;
+  height: 1px !important;
+  padding: 0 !important;
+  overflow: hidden !important;
+  clip: rect(0, 0, 0, 0) !important;
+  white-space: nowrap !important;
+  border: 0 !important;
+}
+
 .region-outline {
   position: absolute;
   inset: 8% 10% 9% 9%;
diff --git a/apps/web/components/workflow-studio.tsx b/apps/web/components/workflow-studio.tsx
index f9a47ad..f66a434 100644
--- a/apps/web/components/workflow-studio.tsx
+++ b/apps/web/components/workflow-studio.tsx
@@ -21,36 +21,76 @@ import {
   UploadSimpleIcon,
   WarningCircleIcon,
 } from "@phosphor-icons/react";
-import Image from "next/image";
-import { FormEvent, useEffect, useMemo, useState } from "react";
+import { ChangeEvent, FormEvent, useEffect, useMemo, useRef, useState } from "react";
 
 import { SettingsCenter } from "@/components/settings-center";
-import {
-  initialLayers,
-  initialMessages,
-  styleDirections,
-  workflowStages,
-} from "@/lib/demo";
-import type { ChatMessage } from "@/types/workflow";
+import { styleDirections } from "@/lib/demo";
+import type { ChatMessage, PlanLayer, ProjectSnapshot, WorkflowStage } from "@/types/workflow";
 import type { SettingsReadiness } from "@/types/settings";
 
 const iconWeight = "regular" as const;
 const API_BASE = process.env.NEXT_PUBLIC_API_BASE_URL ?? "http://localhost:8000";
+const stageMeta: Array<Pick<WorkflowStage, "id" | "label" | "detail">> = [
+  { id: "uploaded", label: "导入图纸", detail: "PDF 原文件" },
+  { id: "region_selection", label: "选择户型", detail: "候选区域" },
+  { id: "plan_review", label: "确认结构", detail: "墙、门窗与比例" },
+  { id: "blockout", label: "生成白模", detail: "空间骨架" },
+  { id: "style_brief", label: "明确风格", detail: "Style DNA" },
+  { id: "direction_selection", label: "选择方向", detail: "三个方案" },
+  { id: "render_review", label: "审阅效果", detail: "多视角" },
+  { id: "editing", label: "多轮修改", detail: "局部编辑" },
+];
 
 export function WorkflowStudio() {
-  const [layers, setLayers] = useState(initialLayers);
+  const [project, setProject] = useState<ProjectSnapshot | null>(null);
+  const [layers, setLayers] = useState<PlanLayer[]>([]);
   const [selectedDirection, setSelectedDirection] = useState("quiet-modern");
-  const [messages, setMessages] = useState<ChatMessage[]>(initialMessages);
+  const [messages, setMessages] = useState<ChatMessage[]>([]);
   const [draft, setDraft] = useState("");
   const [furnitureMode, setFurnitureMode] = useState<"reference" | "remove">("reference");
   const [settingsOpen, setSettingsOpen] = useState(false);
   const [readiness, setReadiness] = useState<SettingsReadiness | null>(null);
+  const [uploading, setUploading] = useState(false);
+  const [workflowError, setWorkflowError] = useState<string | null>(null);
+  const fileInputRef = useRef<HTMLInputElement>(null);
 
   const currentDirection = useMemo(
     () => styleDirections.find((item) => item.id === selectedDirection) ?? styleDirections[0],
     [selectedDirection],
   );
 
+  const workflowStages = useMemo<WorkflowStage[]>(() => {
+    const activeIndex = project ? stageMeta.findIndex((item) => item.id === project.stage) : -1;
+    return stageMeta.map((stage, index) => ({
+      ...stage,
+      status: activeIndex < 0 ? "pending" : index < activeIndex ? "complete" : index === activeIndex ? "active" : "pending",
+    }));
+  }, [project]);
+
+  const selectedRegion = useMemo(
+    () => project?.plan.regions.find((region) => region.id === project.plan.selected_region_id) ?? null,
+    [project],
+  );
+
+  function applyProject(next: ProjectSnapshot) {
+    setProject(next);
+    setLayers(next.plan.layers.map((layer) => ({ ...layer, count: layer.element_count ?? undefined })));
+    setMessages([
+      ...next.plan.ingestion_notes.map((body, index) => ({
+        id: `ingestion-${index}`,
+        role: "assistant" as const,
+        body,
+        meta: "图纸解析",
+      })),
+      ...next.plan.issues.filter((issue) => !issue.resolved).map((issue) => ({
+        id: `issue-${issue.id}`,
+        role: "assistant" as const,
+        body: issue.message,
+        meta: "等待确认",
+      })),
+    ]);
+  }
+
   useEffect(() => {
     async function loadReadiness() {
       try {
@@ -67,8 +107,73 @@ export function WorkflowStudio() {
       }
     }
     void loadReadiness();
+    fetch(`${API_BASE}/v1/projects`, { cache: "no-store" })
+      .then((response) => response.ok ? response.json() as Promise<ProjectSnapshot[]> : [])
+      .then((projects) => {
+        const latest = projects.find((item) => item.project_id !== "demo-apartment");
+        if (latest) applyProject(latest);
+      })
+      .catch(() => undefined);
   }, []);
 
+  async function readApiError(response: Response, fallback: string) {
+    try {
+      const payload = await response.json() as { detail?: string | { message?: string } };
+      if (typeof payload.detail === "string") return payload.detail;
+      if (payload.detail?.message) return payload.detail.message;
+    } catch {
+      // Keep the readable fallback.
+    }
+    return fallback;
+  }
+
+  async function uploadPlan(file: File) {
+    if (!readiness?.ready) {
+      setSettingsOpen(true);
+      setWorkflowError("请先完成系统设置和真实生图验证。");
+      return;
+    }
+    setUploading(true);
+    setWorkflowError(null);
+    const form = new FormData();
+    form.append("file", file);
+    form.append("project_name", `${file.name.replace(/\.pdf$/i, "")} 概念方案`);
+    try {
+      const response = await fetch(`${API_BASE}/v1/projects/ingest`, { method: "POST", body: form });
+      if (!response.ok) throw new Error(await readApiError(response, "图纸上传或解析失败。"));
+      applyProject(await response.json() as ProjectSnapshot);
+    } catch (error) {
+      setWorkflowError(error instanceof Error ? error.message : "图纸上传或解析失败。");
+    } finally {
+      setUploading(false);
+      if (fileInputRef.current) fileInputRef.current.value = "";
+    }
+  }
+
+  function chooseFile(event: ChangeEvent<HTMLInputElement>) {
+    const file = event.target.files?.[0];
+    if (file) void uploadPlan(file);
+  }
+
+  async function selectRegion(regionId: string) {
+    if (!project || project.stage !== "region_selection") return;
+    setWorkflowError(null);
+    const response = await fetch(`${API_BASE}/v1/projects/${project.project_id}/commands`, {
+      method: "POST",
+      headers: { "Content-Type": "application/json" },
+      body: JSON.stringify({
+        command: "select_region",
+        expected_revision: project.revision,
+        payload: { region_id: regionId },
+      }),
+    });
+    if (!response.ok) {
+      setWorkflowError(await readApiError(response, "候选户型选择失败。"));
+      return;
+    }
+    applyProject(await response.json() as ProjectSnapshot);
+  }
+
   function toggleLayer(id: string) {
     setLayers((items) =>
       items.map((item) => (item.id === id ? { ...item, visible: !item.visible } : item)),
@@ -102,7 +207,7 @@ export function WorkflowStudio() {
             </div>
             <div>
               <p className="brand-name">空间风格工作台</p>
-              <p className="brand-subtitle">11-2-104 住宅概念方案</p>
+              <p className="brand-subtitle">{project?.name ?? "新建住宅概念方案"}</p>
             </div>
           </div>
 
@@ -116,12 +221,13 @@ export function WorkflowStudio() {
             <button
               className="button button-primary"
               type="button"
-              disabled={!readiness?.ready}
-              onClick={() => { if (!readiness?.ready) setSettingsOpen(true); }}
-              title={!readiness?.ready ? "请先完成系统设置" : undefined}
+              disabled={uploading || Boolean(project)}
+              onClick={() => readiness?.ready ? fileInputRef.current?.click() : setSettingsOpen(true)}
+              title={!readiness?.ready ? "请先完成系统设置" : project ? "当前阶段请在图纸上完成候选区域确认" : undefined}
             >
-              {readiness?.ready ? "确认结构" : "配置后开始"} <ArrowRightIcon size={16} weight="bold" />
+              {uploading ? "正在解析" : project ? "按图确认" : readiness?.ready ? "导入图纸" : "配置后开始"} <ArrowRightIcon size={16} weight="bold" />
             </button>
+            <input ref={fileInputRef} className="visually-hidden" type="file" accept="application/pdf,.pdf" onChange={chooseFile} />
           </div>
         </header>
 
@@ -129,7 +235,7 @@ export function WorkflowStudio() {
           <aside className="workflow-rail" aria-label="设计流程">
             <div className="rail-heading">
               <p>设计流程</p>
-              <span>3 / 8</span>
+              <span>{project ? Math.max(1, stageMeta.findIndex((item) => item.id === project.stage) + 1) : 0} / 8</span>
             </div>
             <nav className="stage-list">
               {workflowStages.map((stage) => (
@@ -152,7 +258,11 @@ export function WorkflowStudio() {
 
             <div className="rail-note">
               <WarningCircleIcon size={18} weight={iconWeight} />
-              <p>有 2 项需要确认，确认后才能生成空间白模。</p>
+              <p>{project
+                ? project.plan.issues.filter((issue) => !issue.resolved).length > 0
+                  ? `还有 ${project.plan.issues.filter((issue) => !issue.resolved).length} 项图纸问题需要确认。`
+                  : "当前阶段的信息已确认。"
+                : "请先导入一份 PDF 户型图。"}</p>
             </div>
           </aside>
 
@@ -180,80 +290,107 @@ export function WorkflowStudio() {
                     </Tooltip.Trigger>
                     <Tooltip.Portal><Tooltip.Content className="tooltip">适应画布</Tooltip.Content></Tooltip.Portal>
                   </Tooltip.Root>
-                  <button className="button button-secondary compact" type="button">
-                    <UploadSimpleIcon size={16} /> 更换图纸
+                  <button className="button button-secondary compact" type="button" onClick={() => fileInputRef.current?.click()} disabled={uploading}>
+                    <UploadSimpleIcon size={16} /> {project ? "更换图纸" : "导入图纸"}
                   </button>
                 </div>
               </div>
 
               <Tabs.Content value="plan" className="tab-content">
-                <div className="plan-workspace">
-                  <div className="plan-canvas">
-                    <div className="canvas-labels">
-                      <span>上方住宅户型</span>
-                      <span>矢量 PDF · 43 个 CAD 图层</span>
-                    </div>
-                    <div className="plan-image-frame">
-                      <Image
-                        src="/sample-plan.png"
-                        alt="从真实 PDF 中分离出的住宅建筑结构平面图"
-                        fill
-                        priority
-                        sizes="(max-width: 900px) 100vw, 60vw"
-                        className="plan-image"
-                      />
-                      <div className="region-outline" aria-hidden="true" />
-                      <button className="issue-marker issue-one" type="button" aria-label="比例待确认">1</button>
-                      <button className="issue-marker issue-two" type="button" aria-label="家具意图待确认">2</button>
-                    </div>
-                    <div className="canvas-status">
-                      <span><CheckIcon size={14} weight="bold" /> 已分离建筑结构</span>
-                      <span>比例待交叉校准</span>
-                    </div>
+                {!project ? (
+                  <div className="plan-upload-empty">
+                    <div className="upload-emblem"><UploadSimpleIcon size={30} /></div>
+                    <h2>{uploading ? "正在读取和分析图纸" : "导入第一份真实户型图"}</h2>
+                    <p>当前支持 25 MB 以内的 PDF。系统会保留原文件、判断矢量或扫描类型，并检测同页中的多个候选平面区域。</p>
+                    <button className="button button-primary" type="button" onClick={() => fileInputRef.current?.click()} disabled={uploading || !readiness?.ready}>
+                      {uploading ? <CircleNotchIcon className="spin" size={16} /> : <UploadSimpleIcon size={16} />}
+                      {uploading ? "解析中，请稍候" : readiness?.ready ? "选择 PDF 图纸" : "完成设置后导入"}
+                    </button>
+                    {workflowError ? <p className="workflow-error"><WarningCircleIcon size={16} /> {workflowError}</p> : null}
                   </div>
-
-                  <aside className="layer-panel">
-                    <div className="panel-title-row">
-                      <div>
-                        <p className="panel-title">图层</p>
-                        <p className="panel-caption">保留矢量信息</p>
+                ) : (
+                  <div className="plan-workspace">
+                    <div className="plan-canvas">
+                      <div className="canvas-labels">
+                        <span>{selectedRegion?.name ?? `${project.plan.regions.length} 个候选平面区域`}</span>
+                        <span>{project.plan.vector_based ? "矢量 PDF" : "扫描 PDF"} · {project.plan.vector_element_count.toLocaleString()} 个矢量元素</span>
                       </div>
-                      <button className="icon-button small" type="button" aria-label="添加图层">
-                        <PlusIcon size={16} />
-                      </button>
-                    </div>
-                    <div className="layer-list">
-                      {layers.map((layer) => (
-                        <button
-                          className={`layer-row ${layer.visible ? "is-visible" : ""}`}
-                          key={layer.id}
-                          type="button"
-                          onClick={() => toggleLayer(layer.id)}
-                        >
-                          {layer.visible ? <EyeIcon size={17} /> : <EyeSlashIcon size={17} />}
-                          <span>{layer.label}</span>
-                          {layer.count ? <small>{layer.count}</small> : null}
-                        </button>
-                      ))}
+                      <div className="plan-document-frame">
+                        {/* eslint-disable-next-line @next/next/no-img-element -- authenticated runtime preview URL. */}
+                        <img
+                          src={`${API_BASE}/v1/projects/${project.project_id}/preview`}
+                          alt={`${project.name} 的 PDF 首页预览`}
+                          className="plan-document-image"
+                        />
+                        <div className="region-layer" aria-label="候选户型区域">
+                          {project.plan.regions.map((region, index) => {
+                            const [x0, y0, x1, y1] = region.bounds;
+                            const selected = region.id === project.plan.selected_region_id;
+                            return (
+                              <button
+                                className={`detected-region ${selected ? "selected" : ""} ${region.recommended ? "recommended" : ""}`}
+                                key={region.id}
+                                type="button"
+                                style={{ left: `${x0 * 100}%`, top: `${y0 * 100}%`, width: `${(x1 - x0) * 100}%`, height: `${(y1 - y0) * 100}%` }}
+                                onClick={() => void selectRegion(region.id)}
+                                disabled={project.stage !== "region_selection"}
+                                aria-label={`选择${region.name}`}
+                              >
+                                <span>{index + 1}</span>
+                                <strong>{region.name}</strong>
+                                <small>{region.recommended ? "建议选择 · " : ""}{Math.round(region.confidence * 100)}%</small>
+                              </button>
+                            );
+                          })}
+                        </div>
+                      </div>
+                      <div className="canvas-status">
+                        <span><CheckIcon size={14} weight="bold" /> 原图与解析预览已保存至 MinIO</span>
+                        <span>{project.stage === "region_selection" ? "请选择目标户型" : "目标区域已确认"}</span>
+                      </div>
+                      {workflowError ? <p className="workflow-error"><WarningCircleIcon size={16} /> {workflowError}</p> : null}
                     </div>
 
-                    <div className="panel-divider" />
-                    <p className="panel-title">原家具处理</p>
-                    <div className="segmented-control">
-                      <button
-                        type="button"
-                        className={furnitureMode === "reference" ? "active" : ""}
-                        onClick={() => setFurnitureMode("reference")}
-                      >保留参考</button>
-                      <button
-                        type="button"
-                        className={furnitureMode === "remove" ? "active" : ""}
-                        onClick={() => setFurnitureMode("remove")}
-                      >仅看结构</button>
-                    </div>
-                    <p className="helper-text">家具位置用于理解尺度，不锁定款式和材质。</p>
-                  </aside>
-                </div>
+                    <aside className="layer-panel">
+                      <div className="panel-title-row">
+                        <div>
+                          <p className="panel-title">解析内容</p>
+                          <p className="panel-caption">PDF 首页 · {project.plan.page_count} 页文件</p>
+                        </div>
+                      </div>
+                      <div className="layer-list">
+                        {layers.map((layer) => (
+                          <button
+                            className={`layer-row ${layer.visible ? "is-visible" : ""}`}
+                            key={layer.id}
+                            type="button"
+                            onClick={() => toggleLayer(layer.id)}
+                          >
+                            {layer.visible ? <EyeIcon size={17} /> : <EyeSlashIcon size={17} />}
+                            <span>{layer.label}</span>
+                            {layer.count ? <small>{layer.count.toLocaleString()}</small> : null}
+                          </button>
+                        ))}
+                      </div>
+
+                      <div className="panel-divider" />
+                      <p className="panel-title">识别状态</p>
+                      <div className="ingestion-facts">
+                        <span><CheckIcon size={13} /> {project.plan.vector_based ? "矢量信息可用" : "需要视觉分割"}</span>
+                        <span><CheckIcon size={13} /> {project.plan.ocr_used ? "百度 OCR 已参与" : "PDF 文字层可读取"}</span>
+                        <span><WarningCircleIcon size={13} /> 比例尚待交叉确认</span>
+                      </div>
+
+                      <div className="panel-divider" />
+                      <p className="panel-title">原家具处理</p>
+                      <div className="segmented-control">
+                        <button type="button" className={furnitureMode === "reference" ? "active" : ""} onClick={() => setFurnitureMode("reference")}>保留参考</button>
+                        <button type="button" className={furnitureMode === "remove" ? "active" : ""} onClick={() => setFurnitureMode("remove")}>仅看结构</button>
+                      </div>
+                      <p className="helper-text">候选区域确认后，下一阶段会分离墙、门窗、文字与家具意图。</p>
+                    </aside>
+                  </div>
+                )}
               </Tabs.Content>
 
               <Tabs.Content value="blockout" className="tab-content empty-workspace">
@@ -271,6 +408,12 @@ export function WorkflowStudio() {
 
             <section className="conversation" aria-label="设计对话">
               <div className="message-stream">
+                {!project ? (
+                  <article className="message message-assistant">
+                    <span className="assistant-icon"><SparkleIcon size={15} weight="fill" /></span>
+                    <div><small>等待图纸</small><p>导入 PDF 后，我会先判断图纸类型并请你选择目标户型区域。</p></div>
+                  </article>
+                ) : null}
                 {messages.slice(-3).map((message) => (
                   <article className={`message message-${message.role}`} key={message.id}>
                     {message.role === "assistant" ? (
@@ -290,9 +433,10 @@ export function WorkflowStudio() {
                     id="design-instruction"
                     value={draft}
                     onChange={(event) => setDraft(event.target.value)}
-                    placeholder="例如：保留床和窗的位置，客厅更松弛，不要冷灰"
+                    placeholder={project ? "例如：保留床和窗的位置，客厅更松弛，不要冷灰" : "导入图纸后开始对话"}
+                    disabled={!project}
                   />
-                  <button className="send-button" type="submit" aria-label="发送设计指令">
+                  <button className="send-button" type="submit" aria-label="发送设计指令" disabled={!project}>
                     <PaperPlaneTiltIcon size={18} weight="fill" />
                   </button>
                 </div>
@@ -311,7 +455,7 @@ export function WorkflowStudio() {
 
             <div className="style-section">
               <label htmlFor="style-concept">设计概念</label>
-              <textarea id="style-concept" defaultValue="温暖、克制、带自然材质感的现代住宅" />
+              <textarea key={project?.project_id ?? "empty"} id="style-concept" defaultValue={project?.style.concept ?? "导入图纸后建立 Style DNA"} disabled={!project} />
             </div>
 
             <div className="style-section">
diff --git a/apps/web/types/workflow.ts b/apps/web/types/workflow.ts
index 28fc9c8..b860adc 100644
--- a/apps/web/types/workflow.ts
+++ b/apps/web/types/workflow.ts
@@ -19,8 +19,76 @@ export interface WorkflowStage {
 export interface PlanLayer {
   id: string;
   label: string;
+  category?: string;
   visible: boolean;
   count?: number;
+  element_count?: number | null;
+  source_names?: string[];
+}
+
+export interface PlanRegion {
+  id: string;
+  name: string;
+  bounds: [number, number, number, number];
+  recommended: boolean;
+  confidence: number;
+}
+
+export interface PlanIssue {
+  id: string;
+  kind: string;
+  message: string;
+  confidence: number;
+  resolved: boolean;
+}
+
+export interface PlanState {
+  source_name: string;
+  source_kind: string;
+  source_object_key?: string | null;
+  preview_object_key?: string | null;
+  preview_width?: number | null;
+  preview_height?: number | null;
+  page_count: number;
+  vector_based: boolean;
+  vector_element_count: number;
+  cad_layer_count: number;
+  ocr_used: boolean;
+  ocr_labels: string[];
+  ingestion_notes: string[];
+  regions: PlanRegion[];
+  selected_region_id?: string | null;
+  layers: PlanLayer[];
+  issues: PlanIssue[];
+  scale_mm_per_unit?: number | null;
+  ceiling_height_mm: number;
+}
+
+export interface ProjectSnapshot {
+  project_id: string;
+  name: string;
+  stage: WorkflowStageId | "failed";
+  revision: number;
+  plan: PlanState;
+  scene: {
+    blockout_asset_key?: string | null;
+    cameras: Array<{ id: string; label: string; room: string; status: string }>;
+    locked_object_ids: string[];
+    furniture_mode: string;
+  };
+  style: {
+    concept: string;
+    keywords: string[];
+    palette: Array<{ name: string; hex: string; role: string }>;
+    materials: string[];
+    lighting: string;
+    forms: string;
+    density: string;
+    avoid: string[];
+    locked_decisions: string[];
+  };
+  available_commands: string[];
+  updated_at: string;
 }
 
 export interface StyleDirection {
diff --git a/contracts/workflow-contract.md b/contracts/workflow-contract.md
index d0c5b3d..5df676d 100644
--- a/contracts/workflow-contract.md
+++ b/contracts/workflow-contract.md
@@ -39,3 +39,11 @@
 - `GET /v1/readiness`：供前端决定是否解锁设计工作流。
 
 任何密钥字段都不会出现在 `values` 中，只会在 `configured` 中返回布尔值。必备配置未完成或测试未通过时，上传与命令接口返回 `503` 和 `SETTINGS_INCOMPLETE`。
+
+## Project Ingestion
+
+- `GET /v1/projects`：按更新时间返回持久化项目。
+- `POST /v1/projects/ingest`：以 `multipart/form-data` 上传 `file`，可选 `project_name`；当前接受 25 MB 以内 PDF。
+- `GET /v1/projects/{project_id}/preview`：从 MinIO 派生文件桶读取 PDF 首页预览。
+- 新项目初始阶段为 `region_selection`，`plan.regions` 提供归一化的 `[x0, y0, x1, y1]` 候选区域。
+- `select_region` 必须引用真实存在的候选区域 ID，成功后修订号递增并进入 `plan_review`。
diff --git a/docs/workflow.md b/docs/workflow.md
index 9c8756b..f082646 100644
--- a/docs/workflow.md
+++ b/docs/workflow.md
@@ -30,6 +30,17 @@ uploaded
 | `apply_edit` | 执行局部或全局修改 | 只变更受影响的状态与视角 |
 | `complete_project` | 完成当前概念方案 | 输出仍标注为概念效果图 |
 
+## 当前已实现的图纸导入
+
+1. 网页通过 API 上传 PDF，API 同时将原文件保存到 MinIO 的原始图纸桶。
+2. PDF 首页被渲染为 PNG 并保存到派生文件桶。
+3. 解析器统计矢量线、矩形与曲线数量，判断矢量或扫描来源。
+4. 基于页面墨迹连通区域检测一页中的多个平面候选区，不自动把整页当作唯一户型。
+5. 用户在预览上明确选择目标区域后，工作流从 `region_selection` 进入 `plan_review`。
+6. 项目快照、修订号和选择结果写入 PostgreSQL，API 重启后仍可恢复。
+
+第一版限制为 PDF、25 MB、首页候选区域检测；多页选择、墙门窗语义分割与比例求解继续在 `plan_review` 阶段实现。
+
 ## Agent 分工
 
 - Orchestrator：确定下一步、追问缺失条件、调度任务、处理失败和回滚。
diff --git a/services/api/app/api/routes.py b/services/api/app/api/routes.py
index 31c61d5..bd131f8 100644
--- a/services/api/app/api/routes.py
+++ b/services/api/app/api/routes.py
@@ -1,23 +1,37 @@
+from pathlib import Path
+from typing import Any
 from uuid import uuid4
 
-from fastapi import APIRouter, Depends, HTTPException, status
+from fastapi import APIRouter, Depends, File, Form, HTTPException, Response, UploadFile, status
 from pydantic import BaseModel
 
 from app.config import Settings, get_settings
 from app.api.settings import require_workflow_ready
-from app.domain.models import CommandRequest, ProjectSnapshot, WorkflowDefinition
+from app.domain.models import (
+    CommandRequest,
+    PlanIssue,
+    PlanLayer,
+    PlanState,
+    ProjectSnapshot,
+    WorkflowDefinition,
+    WorkflowStage,
+)
 from app.domain.workflow import (
     InvalidTransitionError,
     WorkflowConflictError,
     apply_command,
+    available_commands,
     workflow_definition,
 )
 from app.integrations.model_router import ModelRouter
+from app.integrations.ocr import BaiduOcrAdapter
 from app.integrations.storage import S3Storage
-from app.repositories.memory import repository
+from app.repositories.postgres import postgres_repository
 from app.runtime_settings import EncryptedSettingsStore, get_runtime_store
+from app.services.plan_ingestion import inspect_pdf
 
 router = APIRouter(prefix="/v1")
+MAX_UPLOAD_BYTES = 25 * 1024 * 1024
 
 
 class UploadRequest(BaseModel):
@@ -25,6 +39,10 @@ class UploadRequest(BaseModel):
     content_type: str
 
 
+def get_project_repository(settings: Settings = Depends(get_settings)):
+    return postgres_repository(settings.database_url)
+
+
 @router.get("/health")
 def health(
     settings: Settings = Depends(get_settings),
@@ -61,19 +79,31 @@ def get_workflow() -> WorkflowDefinition:
 
 
 @router.get("/projects/{project_id}", response_model=ProjectSnapshot)
-def get_project(project_id: str) -> ProjectSnapshot:
+def get_project(
+    project_id: str,
+    repository: Any = Depends(get_project_repository),
+) -> ProjectSnapshot:
     project = repository.get(project_id)
     if project is None:
         raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Project not found.")
     return project
 
 
+@router.get("/projects", response_model=list[ProjectSnapshot])
+def list_projects(repository: Any = Depends(get_project_repository)) -> list[ProjectSnapshot]:
+    return repository.list()
+
+
 @router.post(
     "/projects/{project_id}/commands",
     response_model=ProjectSnapshot,
     dependencies=[Depends(require_workflow_ready)],
 )
-def execute_command(project_id: str, request: CommandRequest) -> ProjectSnapshot:
+def execute_command(
+    project_id: str,
+    request: CommandRequest,
+    repository: Any = Depends(get_project_repository),
+) -> ProjectSnapshot:
     project = repository.get(project_id)
     if project is None:
         raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Project not found.")
@@ -86,6 +116,148 @@ def execute_command(project_id: str, request: CommandRequest) -> ProjectSnapshot
     return repository.save(updated)
 
 
+@router.post(
+    "/projects/ingest",
+    response_model=ProjectSnapshot,
+    dependencies=[Depends(require_workflow_ready)],
+)
+async def ingest_project(
+    file: UploadFile = File(...),
+    project_name: str = Form(""),
+    runtime_store: EncryptedSettingsStore = Depends(get_runtime_store),
+    repository: Any = Depends(get_project_repository),
+) -> ProjectSnapshot:
+    filename = (file.filename or "floor-plan.pdf").strip()
+    if Path(filename).suffix.lower() != ".pdf":
+        raise HTTPException(status_code=415, detail="当前阶段只支持 PDF 户型图。")
+    content = await file.read(MAX_UPLOAD_BYTES + 1)
+    if not content:
+        raise HTTPException(status_code=422, detail="上传文件为空。")
+    if len(content) > MAX_UPLOAD_BYTES:
+        raise HTTPException(status_code=413, detail="PDF 不能超过 25 MB。")
+    try:
+        inspection = inspect_pdf(content)
+    except ValueError as exc:
+        raise HTTPException(status_code=422, detail=str(exc)) from exc
+
+    values = runtime_store.merged_values()
+    storage = S3Storage(values)
+    project_id = str(uuid4())
+    safe_name = filename.replace("/", "_").replace("\\", "_")
+    source_key = f"projects/{project_id}/source/{safe_name}"
+    preview_key = f"projects/{project_id}/derived/page-1-preview.png"
+    try:
+        storage.put_input(source_key, content, file.content_type or "application/pdf")
+        storage.put_output(preview_key, inspection.preview_png, "image/png")
+    except Exception as exc:
+        raise HTTPException(status_code=503, detail=f"图纸写入 MinIO 失败：{exc}") from exc
+
+    ocr_labels: list[str] = []
+    ocr_used = False
+    ocr = BaiduOcrAdapter(values)
+    if inspection.text_is_corrupted and ocr.configured:
+        try:
+            ocr_result = await ocr.recognize(inspection.preview_png)
+            ocr_labels = [str(row.get("words", "")).strip() for row in ocr_result if row.get("words")]
+            ocr_used = bool(ocr_labels)
+        except Exception:
+            ocr_labels = []
+
+    notes = [
+        f"首页检测到 {inspection.vector_element_count} 个矢量元素。"
+        if inspection.vector_based
+        else "首页主要由像素图像组成，后续需要视觉分割。",
+        f"检测到 {len(inspection.regions)} 个候选平面区域，请由用户确认目标户型。",
+    ]
+    if inspection.text_is_corrupted:
+        notes.append("原 PDF 文字层不可可靠读取，已调用百度 OCR。" if ocr_used else "原 PDF 文字层不可可靠读取，需要 OCR 或人工确认。")
+    else:
+        notes.append("原 PDF 文字层可读取，尺寸文字仍需和图形标注交叉校验。")
+
+    issues = [
+        PlanIssue(
+            id="region-selection",
+            kind="region",
+            message=f"检测到 {len(inspection.regions)} 个候选区域，请选择需要设计的户型。",
+            confidence=max((region.confidence for region in inspection.regions), default=0.5),
+        ),
+        PlanIssue(
+            id="scale-check",
+            kind="scale",
+            message="比例需要结合至少两个尺寸标注交叉确认。",
+            confidence=0.55,
+        ),
+    ]
+    if inspection.text_is_corrupted and not ocr_used:
+        issues.append(
+            PlanIssue(
+                id="text-recovery",
+                kind="ocr",
+                message="房间名称与尺寸文字尚未可靠识别。",
+                confidence=0.35,
+            )
+        )
+
+    stage = WorkflowStage.REGION_SELECTION
+    project = ProjectSnapshot(
+        project_id=project_id,
+        name=project_name.strip() or f"{Path(filename).stem} 概念方案",
+        stage=stage,
+        plan=PlanState(
+            source_name=filename,
+            source_kind="vector_pdf" if inspection.vector_based else "scanned_pdf",
+            source_object_key=source_key,
+            preview_object_key=preview_key,
+            preview_width=inspection.preview_width,
+            preview_height=inspection.preview_height,
+            page_count=inspection.page_count,
+            vector_based=inspection.vector_based,
+            vector_element_count=inspection.vector_element_count,
+            regions=inspection.regions,
+            layers=[
+                PlanLayer(
+                    id="pdf-vector",
+                    label="PDF 矢量线稿",
+                    category="raw_vector",
+                    visible=True,
+                    element_count=inspection.vector_element_count,
+                ),
+                PlanLayer(
+                    id="pdf-text",
+                    label="尺寸与房间文字",
+                    category="annotation",
+                    visible=True,
+                    element_count=len(ocr_labels) if ocr_used else len(inspection.extracted_text),
+                ),
+            ],
+            issues=issues,
+            ocr_used=ocr_used,
+            ocr_labels=ocr_labels[:300],
+            ingestion_notes=notes,
+        ),
+        available_commands=available_commands(stage),
+    )
+    return repository.save(project)
+
+
+@router.get("/projects/{project_id}/preview")
+def get_project_preview(
+    project_id: str,
+    runtime_store: EncryptedSettingsStore = Depends(get_runtime_store),
+    repository: Any = Depends(get_project_repository),
+) -> Response:
+    project = repository.get(project_id)
+    if project is None:
+        raise HTTPException(status_code=404, detail="Project not found.")
+    if not project.plan.preview_object_key:
+        raise HTTPException(status_code=404, detail="Project preview is not available.")
+    try:
+        content, content_type = S3Storage(runtime_store.merged_values()).get_output(project.plan.preview_object_key)
+    except Exception as exc:
+        raise HTTPException(status_code=503, detail=f"读取图纸预览失败：{exc}") from exc
+    return Response(content=content, media_type=content_type, headers={"Cache-Control": "private, max-age=60"})
+
+
 @router.post("/uploads/presign", dependencies=[Depends(require_workflow_ready)])
 def create_upload(
     request: UploadRequest,
diff --git a/services/api/app/domain/models.py b/services/api/app/domain/models.py
index df0cd08..9115f51 100644
--- a/services/api/app/domain/models.py
+++ b/services/api/app/domain/models.py
@@ -50,6 +50,7 @@ class PlanLayer(BaseModel):
     category: str
     visible: bool = True
     source_names: list[str] = Field(default_factory=list)
+    element_count: int | None = None
 
 
 class PlanIssue(BaseModel):
@@ -63,9 +64,17 @@ class PlanIssue(BaseModel):
 class PlanState(BaseModel):
     source_name: str
     source_kind: str
+    source_object_key: str | None = None
+    preview_object_key: str | None = None
+    preview_width: int | None = None
+    preview_height: int | None = None
     page_count: int = 1
     vector_based: bool = False
+    vector_element_count: int = 0
     cad_layer_count: int = 0
+    ocr_used: bool = False
+    ocr_labels: list[str] = Field(default_factory=list)
+    ingestion_notes: list[str] = Field(default_factory=list)
     regions: list[PlanRegion] = Field(default_factory=list)
     selected_region_id: str | None = None
     layers: list[PlanLayer] = Field(default_factory=list)
diff --git a/services/api/app/domain/workflow.py b/services/api/app/domain/workflow.py
index f5fe09a..6ba1de9 100644
--- a/services/api/app/domain/workflow.py
+++ b/services/api/app/domain/workflow.py
@@ -80,7 +80,13 @@ def apply_command(project: ProjectSnapshot, request: CommandRequest) -> ProjectS
     updated.failure_reason = None
 
     if request.command == WorkflowCommand.SELECT_REGION:
-        updated.plan.selected_region_id = request.payload.get("region_id")
+        region_id = str(request.payload.get("region_id", ""))
+        if not any(region.id == region_id for region in updated.plan.regions):
+            raise InvalidTransitionError(f"Region '{region_id}' does not exist in this project.")
+        updated.plan.selected_region_id = region_id
+        for issue in updated.plan.issues:
+            if issue.kind == "region":
+                issue.resolved = True
     elif request.command == WorkflowCommand.CONFIRM_PLAN:
         updated.plan.ceiling_height_mm = int(
             request.payload.get("ceiling_height_mm", updated.plan.ceiling_height_mm)
diff --git a/services/api/app/integrations/storage.py b/services/api/app/integrations/storage.py
index d3a24f1..dbf7e35 100644
--- a/services/api/app/integrations/storage.py
+++ b/services/api/app/integrations/storage.py
@@ -1,5 +1,6 @@
 from dataclasses import dataclass
 from collections.abc import Mapping
+from io import BytesIO
 from typing import Any
 
 import boto3
@@ -70,3 +71,28 @@ class S3Storage:
             object_key=object_key,
             expires_in=int(self._value("s3_presigned_url_ttl_seconds", 900)),
         )
+
+    def put_input(self, object_key: str, content: bytes, content_type: str) -> None:
+        self._put(self._value("s3_bucket_inputs"), object_key, content, content_type)
+
+    def put_output(self, object_key: str, content: bytes, content_type: str) -> None:
+        self._put(self._value("s3_bucket_derived"), object_key, content, content_type)
+
+    def get_output(self, object_key: str) -> tuple[bytes, str]:
+        if not self.configured:
+            raise RuntimeError("MinIO/S3 is not configured.")
+        response = self._client().get_object(
+            Bucket=self._value("s3_bucket_derived"),
+            Key=object_key,
+        )
+        return response["Body"].read(), response.get("ContentType", "application/octet-stream")
+
+    def _put(self, bucket: str, object_key: str, content: bytes, content_type: str) -> None:
+        if not self.configured:
+            raise RuntimeError("MinIO/S3 is not configured.")
+        self._client().upload_fileobj(
+            BytesIO(content),
+            bucket,
+            object_key,
+            ExtraArgs={"ContentType": content_type},
+        )
diff --git a/services/api/app/repositories/memory.py b/services/api/app/repositories/memory.py
index 8717f3c..6153b28 100644
--- a/services/api/app/repositories/memory.py
+++ b/services/api/app/repositories/memory.py
@@ -123,6 +123,9 @@ class InMemoryProjectRepository:
     def get(self, project_id: str) -> ProjectSnapshot | None:
         return self._items.get(project_id)
 
+    def list(self) -> list[ProjectSnapshot]:
+        return sorted(self._items.values(), key=lambda item: item.updated_at, reverse=True)
+
     def save(self, project: ProjectSnapshot) -> ProjectSnapshot:
         self._items[project.project_id] = project
         return project
diff --git a/services/api/app/repositories/postgres.py b/services/api/app/repositories/postgres.py
new file mode 100644
index 0000000..8275763
--- /dev/null
+++ b/services/api/app/repositories/postgres.py
@@ -0,0 +1,84 @@
+from __future__ import annotations
+
+import json
+from functools import lru_cache
+
+import psycopg
+from psycopg.types.json import Jsonb
+
+from app.domain.models import ProjectSnapshot
+from app.repositories.memory import create_demo_project
+
+
+class PostgresProjectRepository:
+    def __init__(self, database_url: str) -> None:
+        self.database_url = database_url
+        self.ensure_schema()
+        if self.get("demo-apartment") is None:
+            self.save(create_demo_project())
+
+    def _connect(self):
+        return psycopg.connect(self.database_url)
+
+    def ensure_schema(self) -> None:
+        with self._connect() as connection, connection.cursor() as cursor:
+            cursor.execute(
+                """
+                CREATE TABLE IF NOT EXISTS projects (
+                    project_id TEXT PRIMARY KEY,
+                    name TEXT NOT NULL,
+                    stage TEXT NOT NULL,
+                    revision INTEGER NOT NULL,
+                    snapshot JSONB NOT NULL,
+                    updated_at TIMESTAMPTZ NOT NULL
+                )
+                """
+            )
+
+    def get(self, project_id: str) -> ProjectSnapshot | None:
+        with self._connect() as connection, connection.cursor() as cursor:
+            cursor.execute("SELECT snapshot FROM projects WHERE project_id = %s", (project_id,))
+            row = cursor.fetchone()
+        if row is None:
+            return None
+        payload = json.loads(row[0]) if isinstance(row[0], str) else row[0]
+        return ProjectSnapshot.model_validate(payload)
+
+    def list(self) -> list[ProjectSnapshot]:
+        with self._connect() as connection, connection.cursor() as cursor:
+            cursor.execute("SELECT snapshot FROM projects ORDER BY updated_at DESC")
+            rows = cursor.fetchall()
+        return [
+            ProjectSnapshot.model_validate(json.loads(row[0]) if isinstance(row[0], str) else row[0])
+            for row in rows
+        ]
+
+    def save(self, project: ProjectSnapshot) -> ProjectSnapshot:
+        payload = project.model_dump(mode="json")
+        with self._connect() as connection, connection.cursor() as cursor:
+            cursor.execute(
+                """
+                INSERT INTO projects (project_id, name, stage, revision, snapshot, updated_at)
+                VALUES (%s, %s, %s, %s, %s, %s)
+                ON CONFLICT (project_id) DO UPDATE SET
+                    name = EXCLUDED.name,
+                    stage = EXCLUDED.stage,
+                    revision = EXCLUDED.revision,
+                    snapshot = EXCLUDED.snapshot,
+                    updated_at = EXCLUDED.updated_at
+                """,
+                (
+                    project.project_id,
+                    project.name,
+                    project.stage.value,
+                    project.revision,
+                    Jsonb(payload),
+                    project.updated_at,
+                ),
+            )
+        return project
+
+
+@lru_cache(maxsize=4)
+def postgres_repository(database_url: str) -> PostgresProjectRepository:
+    return PostgresProjectRepository(database_url)
diff --git a/services/api/app/services/__init__.py b/services/api/app/services/__init__.py
new file mode 100644
index 0000000..b00104f
--- /dev/null
+++ b/services/api/app/services/__init__.py
@@ -0,0 +1 @@
+"""Application services for document ingestion and workflow execution."""
diff --git a/services/api/app/services/plan_ingestion.py b/services/api/app/services/plan_ingestion.py
new file mode 100644
index 0000000..3b08bf1
--- /dev/null
+++ b/services/api/app/services/plan_ingestion.py
@@ -0,0 +1,166 @@
+from __future__ import annotations
+
+from dataclasses import dataclass
+from io import BytesIO
+from math import prod
+from typing import Any
+
+import pdfplumber
+import pypdfium2 as pdfium
+from PIL import Image, ImageFilter
+
+from app.domain.models import PlanRegion
+
+
+@dataclass(frozen=True)
+class PdfIngestionResult:
+    page_count: int
+    vector_based: bool
+    vector_element_count: int
+    extracted_text: str
+    text_is_corrupted: bool
+    preview_png: bytes
+    preview_width: int
+    preview_height: int
+    regions: list[PlanRegion]
+
+
+def inspect_pdf(pdf_bytes: bytes) -> PdfIngestionResult:
+    if not pdf_bytes.startswith(b"%PDF-"):
+        raise ValueError("上传内容不是有效的 PDF 文件。")
+    try:
+        with pdfplumber.open(BytesIO(pdf_bytes)) as document:
+            if not document.pages:
+                raise ValueError("PDF 没有可解析的页面。")
+            page = document.pages[0]
+            vector_count = len(page.lines) + len(page.rects) + len(page.curves)
+            extracted_text = page.extract_text() or ""
+            page_count = len(document.pages)
+    except ValueError:
+        raise
+    except Exception as exc:
+        raise ValueError(f"PDF 解析失败：{exc}") from exc
+
+    preview = _render_first_page(pdf_bytes)
+    preview_png = BytesIO()
+    preview.save(preview_png, format="PNG", optimize=True)
+    return PdfIngestionResult(
+        page_count=page_count,
+        vector_based=vector_count >= 80,
+        vector_element_count=vector_count,
+        extracted_text=extracted_text,
+        text_is_corrupted=_text_looks_corrupted(extracted_text),
+        preview_png=preview_png.getvalue(),
+        preview_width=preview.width,
+        preview_height=preview.height,
+        regions=detect_plan_regions(preview),
+    )
+
+
+def _render_first_page(pdf_bytes: bytes) -> Image.Image:
+    try:
+        document = pdfium.PdfDocument(pdf_bytes)
+        page = document[0]
+        width, _ = page.get_size()
+        scale = max(0.75, min(2.0, 1600 / max(width, 1)))
+        image = page.render(scale=scale).to_pil().convert("RGB")
+        page.close()
+        document.close()
+        return image
+    except Exception as exc:
+        raise ValueError(f"PDF 首页渲染失败：{exc}") from exc
+
+
+def _text_looks_corrupted(text: str) -> bool:
+    compact = [character for character in text if not character.isspace()]
+    if len(compact) < 8:
+        return True
+    cjk = sum("\u3400" <= character <= "\u9fff" for character in compact)
+    ascii_useful = sum(character.isascii() and (character.isalnum() or character in "-./") for character in compact)
+    non_cjk_letters = sum(character.isalpha() and not character.isascii() and not ("\u3400" <= character <= "\u9fff") for character in compact)
+    useful_ratio = (cjk + ascii_useful) / len(compact)
+    return useful_ratio < 0.45 or (cjk == 0 and non_cjk_letters >= 6)
+
+
+def detect_plan_regions(image: Image.Image) -> list[PlanRegion]:
+    analysis = image.convert("L")
+    analysis.thumbnail((420, 640), Image.Resampling.LANCZOS)
+    width, height = analysis.size
+    ink = analysis.point(lambda value: 255 if value < 235 else 0)
+    connected = ink.filter(ImageFilter.MaxFilter(9)).filter(ImageFilter.MaxFilter(7))
+    pixels = connected.load()
+    visited = bytearray(width * height)
+    components: list[dict[str, Any]] = []
+
+    for y in range(height):
+        for x in range(width):
+            index = y * width + x
+            if visited[index] or pixels[x, y] == 0:
+                continue
+            stack = [(x, y)]
+            visited[index] = 1
+            min_x = max_x = x
+            min_y = max_y = y
+            count = 0
+            while stack:
+                current_x, current_y = stack.pop()
+                count += 1
+                min_x = min(min_x, current_x)
+                max_x = max(max_x, current_x)
+                min_y = min(min_y, current_y)
+                max_y = max(max_y, current_y)
+                for next_y in range(max(0, current_y - 1), min(height, current_y + 2)):
+                    for next_x in range(max(0, current_x - 1), min(width, current_x + 2)):
+                        next_index = next_y * width + next_x
+                        if not visited[next_index] and pixels[next_x, next_y] != 0:
+                            visited[next_index] = 1
+                            stack.append((next_x, next_y))
+            box_width = max_x - min_x + 1
+            box_height = max_y - min_y + 1
+            if box_width < width * 0.14 or box_height < height * 0.11:
+                continue
+            if count < prod((width, height)) * 0.003:
+                continue
+            components.append(
+                {
+                    "box": (min_x, min_y, max_x + 1, max_y + 1),
+                    "count": count,
+                    "density": _ink_density(ink, (min_x, min_y, max_x + 1, max_y + 1)),
+                }
+            )
+
+    if not components:
+        components = [{"box": (0, 0, width, height), "count": width * height, "density": 0.0}]
+    components.sort(key=lambda component: (component["box"][1], component["box"][0]))
+    components = components[:6]
+    best = max(range(len(components)), key=lambda index: components[index]["density"] * components[index]["count"])
+    regions: list[PlanRegion] = []
+    for index, component in enumerate(components):
+        x0, y0, x1, y1 = component["box"]
+        pad_x = width * 0.015
+        pad_y = height * 0.015
+        bounds = [
+            round(max(0.0, (x0 - pad_x) / width), 4),
+            round(max(0.0, (y0 - pad_y) / height), 4),
+            round(min(1.0, (x1 + pad_x) / width), 4),
+            round(min(1.0, (y1 + pad_y) / height), 4),
+        ]
+        vertical_hint = "上方" if (y0 + y1) / 2 < height / 2 else "下方"
+        confidence = min(0.96, 0.64 + component["density"] * 2.4)
+        regions.append(
+            PlanRegion(
+                id=f"region-{index + 1}",
+                name=f"{vertical_hint}候选区域 {index + 1}",
+                bounds=bounds,
+                recommended=index == best,
+                confidence=round(confidence, 2),
+            )
+        )
+    return regions
+
+
+def _ink_density(image: Image.Image, box: tuple[int, int, int, int]) -> float:
+    crop = image.crop(box)
+    histogram = crop.histogram()
+    ink_pixels = sum(histogram[1:])
+    return ink_pixels / max(crop.width * crop.height, 1)
diff --git a/services/api/pyproject.toml b/services/api/pyproject.toml
index 75b07b1..ba36ade 100644
--- a/services/api/pyproject.toml
+++ b/services/api/pyproject.toml
@@ -12,7 +12,10 @@ dependencies = [
   "cryptography>=44,<47",
   "fastapi>=0.115,<1",
   "httpx>=0.28,<1",
+  "pdfplumber>=0.11,<1",
+  "pillow>=11,<13",
   "psycopg[binary]>=3.2,<4",
+  "pypdfium2>=5,<6",
   "pydantic>=2.10,<3",
   "pydantic-settings>=2.7,<3",
   "python-multipart>=0.0.20,<1",
diff --git a/services/api/tests/test_api.py b/services/api/tests/test_api.py
index 0157e83..4319f32 100644
--- a/services/api/tests/test_api.py
+++ b/services/api/tests/test_api.py
@@ -3,7 +3,9 @@ import pytest
 from pathlib import Path
 
 from app.config import Settings
+from app.api.routes import get_project_repository
 from app.main import app
+from app.repositories.memory import InMemoryProjectRepository
 from app.runtime_settings import EncryptedSettingsStore, get_runtime_store
 
 
@@ -17,7 +19,9 @@ def transport(tmp_path: Path) -> httpx.ASGITransport:
             redis_url="redis://:secret@redis:6379/0",
         )
     )
+    repository = InMemoryProjectRepository()
     app.dependency_overrides[get_runtime_store] = lambda: store
+    app.dependency_overrides[get_project_repository] = lambda: repository
     return httpx.ASGITransport(app=app)
 
 
diff --git a/services/api/tests/test_plan_ingestion.py b/services/api/tests/test_plan_ingestion.py
new file mode 100644
index 0000000..ef17287
--- /dev/null
+++ b/services/api/tests/test_plan_ingestion.py
@@ -0,0 +1,19 @@
+from pathlib import Path
+
+from app.services.plan_ingestion import inspect_pdf
+
+
+def test_sample_pdf_detects_two_plan_regions() -> None:
+    workspace = Path(__file__).resolve().parents[3]
+    sample = workspace / "11-2-104-模型.pdf"
+
+    result = inspect_pdf(sample.read_bytes())
+
+    assert result.page_count == 1
+    assert result.vector_based is True
+    assert result.vector_element_count > 10_000
+    assert result.preview_width == 1600
+    assert len(result.regions) == 2
+    assert result.regions[0].name.startswith("上方")
+    assert result.regions[0].recommended is True
+    assert result.regions[1].name.startswith("下方")
diff --git a/services/api/tests/test_workflow.py b/services/api/tests/test_workflow.py
index 1a91872..28830b3 100644
--- a/services/api/tests/test_workflow.py
+++ b/services/api/tests/test_workflow.py
@@ -43,3 +43,17 @@ def test_invalid_command_is_rejected() -> None:
                 expected_revision=project.revision,
             ),
         )
+
+
+def test_unknown_region_is_rejected() -> None:
+    project = create_demo_project()
+    project.stage = WorkflowStage.REGION_SELECTION
+    with pytest.raises(InvalidTransitionError):
+        apply_command(
+            project,
+            CommandRequest(
+                command=WorkflowCommand.SELECT_REGION,
+                expected_revision=project.revision,
+                payload={"region_id": "missing-region"},
+            ),
+        )