diff --git a/A00_Common/design/design_pipeline_page.ts b/A00_Common/design/design_pipeline_page.ts
index e49271760..d5dbe7cd8 100644
--- a/A00_Common/design/design_pipeline_page.ts
+++ b/A00_Common/design/design_pipeline_page.ts
@@ -16,6 +16,7 @@
  * 출력 — 가게 stations · profile · footprint · generation · 노선 초안이 있으면 종단도가 새 첫 계획선 ·
  *   옮긴 계획고 · 새 노선 상세(`pipelineDetail` — 지반 · 측점 · 횡단 면적 → 유토곡선)를 그림.
  * 첫 계산 = 열 때 한 번(저장 노선 · 발자국 · 저장 안 한 노선 초안이 있으면 그 노선).
+ * 노선 초안을 버리면(되돌리기 · [저장 전으로]) 열 때처럼 — 측점 · 종단을 안 내고 초안 전 상세 그대로(349-0k).
  * [저장](sub5)이 서버 정본 — 노선을 먼저 보내고 `pendingAlignment(DRAFT_ROUTE_ID)` 를 새 노선에 보냄.
  * ========================================================================== */
 
@@ -25,6 +26,7 @@ import { createStationsStage } from "./logic/design_pipeline_stations";
 import type {
   FollowPatch,
   PipelineInputs,
+  PipelineOutputs,
   PipelineStation,
   RouteDraft,
   StageFn,
@@ -120,6 +122,12 @@ export interface PagePipelineOptions {
   /** 노선 조작 뒤 follow 가 가게 관 · 구조물을 다시 씀(목록 · 알약 다시) — `far` = 새 노선에서
    *  `STRUCTURE_ROUTE_DRIFT_MAX_M` 넘게 먼 구조물 수(초안을 버려 되돌렸으면 0). */
   onFacilitiesFollowed?: (far: number) => void;
+  /** 노선 초안을 버림(349-0k) — 초안 전 상세(`saved` · 없으면 null)로 되돌림 · `stations` = 저장 노선 측점. */
+  onDraftDropped?: (
+    routeId: number,
+    saved: SectionDetailResponse | null,
+    stations: PipelineStation[],
+  ) => void;
 }
 
 interface PagePipeline {
@@ -212,6 +220,11 @@ function createPagePipeline(
   let disposed = false;
   /** 열 때 · 정본이 바뀐 차례(start) 번호 — 측점 · 종단을 가게에 안 냄(상세 = 저장 정본 그대로). */
   let openGeneration = -1;
+  /** 측점 · 종단을 가게에 안 내는 차례 — 열 때 · 노선 초안을 버린 차례(상세 = 초안 전 상세로 되돌림). */
+  let quietGeneration = -1;
+  /** 노선 초안 전 상세(종단도가 그리던 것) — 초안을 버리면 이것으로(다시 셈 없음 · 349-0k). */
+  let restoreTo: SectionDetailResponse | null = null;
+  let restoring = false;
   /** 노선 초안 전 가게 관 · 구조물 — 초안 동안 follow 가 새 측점을 가게에 씀 · 초안을 버리면 이것으로. */
   let beforeDraft: Facilities | null = null;
   /** 묶음이 가게에 마지막으로 쓴 관 · 구조물 · 쓰는 동안(메아리 — 다시 입력으로 안 받음). */
@@ -295,7 +308,19 @@ function createPagePipeline(
   const publish = publishToStore(store);
   pipe.subscribe((event) => {
     const saved = event.kind === "stage" && (event.stage === "ground" || event.stage === "profile");
-    if (!(saved && event.generation === openGeneration)) publish(event);
+    if (!(saved && event.generation === quietGeneration)) publish(event);
+  });
+  // 노선 초안을 버린 차례 — 저장 노선 측점이 나오면 초안 전 상세로 되돌림(열 때와 같은 길)
+  pipe.subscribe((event) => {
+    if (event.kind !== "stage" || event.stage !== "ground") return;
+    if (!restoring || event.generation !== quietGeneration) return;
+    restoring = false;
+    const routeId = canon?.routeId;
+    const stations = (event.value as PipelineOutputs["ground"] | null)?.stations ?? [];
+    const saved = restoreTo;
+    restoreTo = null;
+    if (typeof routeId === "number" && stations.length)
+      queueMicrotask(() => options.onDraftDropped?.(routeId, saved, stations));
   });
   // 사용자 노선 조작 뒤 follow 가 다시 매긴 관 · 구조물 = 가게(목록 · 알약 · 횡단 보기가 바로 새 측점) ·
   // 초안을 버리면 초안 전 값 · 열 때(start 차례)는 안 씀 — 알림 밖(틱 뒤)에서 씀(쓰기 고리 막음과 안 부딪힘)
@@ -384,8 +409,10 @@ function createPagePipeline(
     if (disposed || !ready || !savedSource().base) return;
     canonChanged();
     started = true;
+    restoreTo = null;
+    restoring = false;
     void pipe.start(inputsNow());
-    openGeneration = pipe.generation;
+    openGeneration = quietGeneration = pipe.generation;
   };
 
   /** 저장 노선(그린 선 · 곡선표 · 기본 반경) · 그 측점 열쇠 — [저장] 뒤 다시 받음(`restart`). */
@@ -440,11 +467,15 @@ function createPagePipeline(
         draft = { ...edit, rev: (stored?.rev ?? 0) + 1, terrain: analysisTerrain(projectId) };
         if (stored && same({ ...stored, rev: 0 }, { ...draft, rev: 0 })) draft = stored;
       }
+      if (draft && !stored && !restoring) restoreTo = savedSource().detail ?? null;
       store.set("routeDraft", draft);
       if (!started) return start();
       const before = pipe.output("route")?.line ?? null;
       const after = draft ? draftLine(draft, plan?.min_radius_m ?? 0).line : savedLine();
+      const generation = pipe.generation;
       void pipe.update("route", draft, routeRange(before, after));
+      restoring = !draft && !!stored && pipe.generation !== generation;
+      if (restoring) quietGeneration = pipe.generation;
     },
   };
 
diff --git a/A00_Common/design/design_view_profile.ts b/A00_Common/design/design_view_profile.ts
index a28ad3914..27de2179b 100644
--- a/A00_Common/design/design_view_profile.ts
+++ b/A00_Common/design/design_view_profile.ts
@@ -48,7 +48,11 @@ import {
   rememberStandardDefaults,
 } from "../../B06_Section/B06_Section_UI_Standard_Panel";
 import { fetchSectionContext } from "../../B06_Section/B06_Section_Api_Fetch";
-import { invalidateSectionDetail } from "../../B06_Section/B06_Section_Section_Store";
+import {
+  invalidateSectionDetail,
+  restoreSectionDetail,
+  swapSectionStations,
+} from "../../B06_Section/B06_Section_Section_Store";
 import {
   onStaleStructureTypes,
   structureAnchorM,
@@ -524,6 +528,14 @@ export async function mountProfileView(
         stationIntervalM: panel.values().stationInterval ?? undefined,
         onCorridorStale: () => sections.setCorridorPending(true),
         onFacilitiesFollowed: followFacilities,
+        // 초안을 버림 — 초안 전 상세 그대로(349-0k) · 그 상세가 없거나(초안 둔 채 새로고침) 측점이 다르면 갈아끼움
+        onDraftDropped: (routeId, saved, stations) =>
+          void (async () => {
+            const back =
+              saved && (await restoreSectionDetail(activeProjectId, routeId, saved, stations));
+            if (!saved || (back && !back.same))
+              await swapSectionStations(activeProjectId, routeId, stations);
+          })(),
       }),
     });
 
diff --git a/B06_Section/B06_Section_Section_Store.ts b/B06_Section/B06_Section_Section_Store.ts
index 036b73f39..749b1977c 100644
--- a/B06_Section/B06_Section_Section_Store.ts
+++ b/B06_Section/B06_Section_Section_Store.ts
@@ -35,6 +35,7 @@ import {
   carryStationKeys,
   registeredKeys,
   stationIntervalOf,
+  stationKeysOf,
   useStationKeyList,
 } from "./B06_Section_Station_Keys";
 import { sameStationList, swapCrossSections } from "./logic/B06_Section_Station_Swap";
@@ -160,6 +161,51 @@ export async function swapSectionStations(
   return { detail: swap.detail, moves: swap.moves };
 }
 
+/**
+ * 노선 초안을 버림(PLAN 349-0k) — 갈아끼운 상세를 초안 전 상세(`saved` · 열 때 받은 저장 정본 객체)로 되돌림 ·
+ * 다시 셈 없음. 측점 열쇠 = 묶음 저장 노선 측점(`stations` · 목록이 같을 때) · 세션 고침 · 조작값 맵은 열쇠로
+ * 넘김(갈아끼움 길 그대로). 이미 그 상세면 null · `same` = 묶음 측점 목록이 그 상세와 같음(1 mm).
+ */
+export async function restoreSectionDetail(
+  projectId: string,
+  routeId: number,
+  saved: SectionDetailResponse,
+  stations: ReadonlyArray<PipelineStation>,
+): Promise<{ detail: SectionDetailResponse; same: boolean } | null> {
+  const key = keyOf(projectId, routeId);
+  const current = cache.get(key);
+  if (!current || current === saved) return null;
+  const sections = saved.cross_sections;
+  const same =
+    sections.length === stations.length &&
+    stations.every((station, i) => Math.abs(station.chainageM - sections[i].chainage_m) < 1e-3);
+  const nextKeys = same
+    ? stations.map((station, i) => ({ key: station.key, chainageM: sections[i].chainage_m }))
+    : stationKeysOf(projectId, sections, stationIntervalOf(saved));
+  const oldKeys = registeredKeys(
+    projectId,
+    routeId,
+    current.cross_sections,
+    stationIntervalOf(current),
+  );
+  const text = (chainageM: number) => chainageM.toFixed(2);
+  const moves = new Map<string, string>();
+  current.cross_sections.forEach((section, i) => {
+    const to = nextKeys.find((entry) => entry.key === oldKeys[i]);
+    if (to && text(to.chainageM) !== text(section.chainage_m))
+      moves.set(text(section.chainage_m), text(to.chainageM));
+  });
+  carryStationKeys(projectId, routeId, nextKeys);
+  cache.set(key, saved);
+  writeState("section-detail", saved, projectId, routeId);
+  await withDraftShapes(saved, projectId);
+  withStructureAreas(saved);
+  if (cache.get(key) !== saved) return null; // 그 사이 다른 갈아끼움 · 새로 받음
+  emitSwap(saved, moves);
+  listeners.get(key)?.forEach((fn) => fn(saved, moves));
+  return { detail: saved, same };
+}
+
 /**
  * 캐시를 비운다. routeId를 생략하면 그 프로젝트 전부 —
  * 서버 쪽 정본이 바뀌었는데 새 상세를 손에 못 쥔 조작(계획선 편집 저장 등) 뒤에 쓴다.
diff --git a/resources/tester/helper_349_0k_undo_saved.cjs b/resources/tester/helper_349_0k_undo_saved.cjs
new file mode 100644
index 000000000..132b0786f
--- /dev/null
+++ b/resources/tester/helper_349_0k_undo_saved.cjs
@@ -0,0 +1,272 @@
+/* PLAN 349-0k sub7 헬퍼 — 열기 → 노선 꼭짓점 끌기 → 되돌리기(초안 버림)면 상세 = 열 때 저장 정본 그대로.
+ * 진짜 TS(`design_pipeline_page` · 단계 파일 · 상세 가게 `B06_Section_Section_Store`)를 트랜스파일해 Node 로 ·
+ * 서버 창구만 가짜. 종단 보기 고리 흉내 = `design_view_profile_sections.followSwap`(가게 stations → 갈아끼움 ·
+ * 새 상세 → render) · `design_view_profile` 의 `onDraftDropped`(되돌림) 그대로. 초안 동안 갈아끼운 횡단은
+ * 브라우저 다시 셈 흉내로 면적을 바꿔 둠(옛 길이면 되돌린 뒤 그 값이 남음).
+ * 입력 argv[2] JSON · argv[3] 격자 이진. 결과 = 표준출력 JSON. 짝 = `test_349_0k_undo_saved.py`. */
+const fs = require("fs");
+const path = require("path");
+const ts = require(path.join(__dirname, "..", "..", "config", "node_modules", "typescript"));
+const CATALOG = require("./helper_322_catalog_module.cjs");
+
+const ROOT = path.join(__dirname, "..", "..");
+const job = JSON.parse(fs.readFileSync(process.argv[2], "utf8"));
+
+function memoryStorage() {
+  const map = new Map();
+  return {
+    getItem: (key) => (map.has(key) ? map.get(key) : null),
+    setItem: (key, value) => map.set(key, String(value)),
+    removeItem: (key) => map.delete(key),
+    key: (index) => [...map.keys()][index] ?? null,
+    get length() {
+      return map.size;
+    },
+  };
+}
+globalThis.window = {
+  sessionStorage: memoryStorage(),
+  localStorage: memoryStorage(),
+  setTimeout,
+  clearTimeout,
+};
+
+// 흙 배분 서버 — 늦게 답함 · 끊기면 버림
+globalThis.fetch = (url, init) =>
+  new Promise((resolve, reject) => {
+    const timer = setTimeout(
+      () => resolve({ ok: true, json: async () => ({ haul_plan: { blocks: [], url } }) }),
+      20,
+    );
+    init.signal.addEventListener("abort", () => {
+      clearTimeout(timer);
+      reject(new Error("aborted"));
+    });
+  });
+
+const STUBS = {};
+const cache = new Map();
+function loadTs(full) {
+  if (cache.has(full)) return cache.get(full);
+  const js = ts.transpileModule(fs.readFileSync(full, "utf8"), {
+    compilerOptions: { module: ts.ModuleKind.CommonJS, target: ts.ScriptTarget.ES2020 },
+  }).outputText;
+  const box = { exports: {} };
+  cache.set(full, box.exports);
+  const localRequire = (request) => {
+    if (CATALOG.isCatalogRequest(request)) return CATALOG;
+    const key = Object.keys(STUBS).find((name) => request.endsWith(name));
+    if (key) return STUBS[key];
+    if (request.startsWith("@config/")) return { API_BASE_URL: "http://fake" };
+    if (request.startsWith("@ui/")) return { showToast: () => undefined };
+    if (request.endsWith(".css")) return {};
+    if (request.endsWith(".json")) return require(path.join(path.dirname(full), request));
+    if (request.startsWith("@util/"))
+      return loadTs(path.join(ROOT, "common_util", `${request.slice(6)}.ts`));
+    if (request.startsWith(".")) return loadTs(path.join(path.dirname(full), `${request}.ts`));
+    return require(request);
+  };
+  new Function("exports", "module", "require", js)(box.exports, box, localRequire);
+  return box.exports;
+}
+const load = (...parts) => loadTs(path.join(ROOT, ...parts));
+
+const sampler = load("common_util", "common_util_surface_sampler.ts");
+const bytes = fs.readFileSync(process.argv[3]);
+const grid = sampler.parseDtmGrid(
+  bytes.buffer.slice(bytes.byteOffset, bytes.byteOffset + bytes.length),
+);
+const local = { grid, design: "las" };
+
+STUBS["B05_Profile_Api_Replan"] = {
+  analysisTerrain: () => "las",
+  fetchRoutePlan: async () => ({
+    planned: job.line,
+    curves: job.curves,
+    min_radius_m: job.minRadius,
+    station_snap: job.stationSnap,
+  }),
+};
+STUBS["B05_Profile_Api_Structures"] = {
+  fetchStructures: async () => ({ structures: [] }),
+  fetchStructureTypes: async () => job.types,
+  readPendingStructures: () => null,
+};
+STUBS["B05_Profile_Api_TerrainGrid"] = {
+  loadDesignTerrainGrid: async () => local,
+  groundStageDeps: () => ({ grid: () => local, remote: async () => [] }),
+};
+STUBS["B04_PreProcess_Api_Fetch"] = {
+  fetchDetailPipePoints: async () => ({
+    pipe_points: job.pipes.map((pipe) => ({ ...pipe, lonlat: [0, 0] })),
+  }),
+};
+STUBS["B06_Section_UI_Standard_Panel"] = { effectiveStandardCross: () => job.standard };
+
+// 구조물 초안 얹기(측점 계획 · 형상) — 이 시험 밖 · 아무 일 없음
+STUBS["B06_Section_Section_Drafts"] = {
+  withDraftStations: async () => undefined,
+  withDraftShapes: async () => undefined,
+  forgetDraftStations: () => undefined,
+};
+STUBS["B06_Section_Api_Fetch"] = {
+  fetchSectionDetail: async () => JSON.parse(JSON.stringify(job.detail)),
+  saveSections: async () => undefined,
+};
+
+const pageMod = load("A00_Common", "design", "design_pipeline_page.ts");
+const storeMod = load("A00_Common", "design", "design_store.ts");
+const sectionStore = load("B06_Section", "B06_Section_Section_Store.ts");
+const alignment = load("B05_Profile", "logic", "B05_Profile_UI_Profile_Alignment.ts");
+const massHaul = load("common_util", "common_util_mass_haul.ts");
+
+const tick = (ms = 0) => new Promise((resolve) => setTimeout(resolve, ms));
+const runs = () => globalThis.__aisloPipeline?.runs ?? [];
+/** 묶음 · 상세 가게가 조용해질 때까지 — 마지막 기록이 끝나고 새 기록이 더 안 생김. */
+async function quiet() {
+  let seen = -1;
+  for (let i = 0; i < 400; i += 1) {
+    await tick(15);
+    const last = runs()[runs().length - 1];
+    const count = runs().length;
+    if (count === seen && (!last || last.outcome !== "running")) return;
+    seen = count;
+  }
+  throw new Error("묶음이 조용해지지 않음");
+}
+const n = job.nodes.length;
+const draftOf = (nodes) => ({
+  nodes,
+  curveOn: Array(n).fill(true),
+  curveRadius: Array(n).fill(null),
+  curveLock: Array(n).fill(null),
+  curveArc: Array(n).fill(null),
+  stationSnap: job.stationSnap,
+});
+const shift = (index, dx, dy) =>
+  job.nodes.map((node, i) => (i === index ? [node[0] + dx, node[1] + dy] : node));
+const sliceRuns = (mark) =>
+  runs()
+    .slice(mark)
+    .map((r) => ({ sources: r.sources, outcome: r.outcome }));
+const finalOf = (detail) => {
+  const [series] = massHaul.computeMassHaulSeries(
+    detail.longitudinal,
+    detail.cross_sections,
+    job.conversion,
+    undefined,
+    ["cross"],
+  );
+  const points = series?.result.points ?? [];
+  return points.length ? points[points.length - 1].cumulative_volume_m3 : null;
+};
+const crossOf = (detail) =>
+  JSON.stringify(detail.cross_sections.map((s) => [s.chainage_m, s.design, s.samples]));
+/** 브라우저 다시 셈 흉내 — 면적 칸(`*_m2`)을 두 배로(카드 · 종단도가 갈아끼운 상세 횡단을 다시 셈). */
+const recompute = (detail) =>
+  detail.cross_sections.forEach((section) => {
+    if (!section.design) return;
+    const design = { ...section.design };
+    for (const [key, value] of Object.entries(design))
+      if (key.endsWith("_m2") && typeof value === "number") design[key] = value * 2;
+    section.design = design;
+  });
+
+async function run() {
+  const P = "proj-349k";
+  const R = 7;
+  window.localStorage.setItem("frd_current_project_id", P);
+  const savedAlignment = job.detail.longitudinal.profile_alignment;
+  const savedBase = alignment.toAlignmentBase(savedAlignment);
+  let detail = await sectionStore.loadSectionDetail(P, R);
+  const opened = detail;
+  const link = {
+    pipelineSource: () => ({ base: savedBase, edits: savedAlignment.edits, detail, routeId: R }),
+    adoptPipeline: (base, edits, draft) =>
+      pageMod.pipelineGrade(P, draft ? edits : savedAlignment.edits),
+    redraw: () => undefined,
+    side: null,
+  };
+  const swaps = [];
+  const restores = [];
+  pageMod.routeDraftBridge(P, link, {
+    stationIntervalM: job.interval,
+    // `design_view_profile` 의 onDraftDropped 그대로
+    onDraftDropped: (routeId, saved, stations) =>
+      void (async () => {
+        const back =
+          saved && (await sectionStore.restoreSectionDetail(P, routeId, saved, stations));
+        restores.push({ saved: !!saved, back: back ? { same: back.same } : null });
+        if (!saved || (back && !back.same))
+          await sectionStore.swapSectionStations(P, routeId, stations);
+      })(),
+  });
+  // followSwap — 새 상세 → 종단도 render(처음부터 다시 · 비정규 측점) · 가게 stations → 갈아끼움
+  const stopListen = sectionStore.subscribeSectionDetail(P, R, (next) => {
+    swaps.push(next.cross_sections.length);
+    detail = next;
+    pageMod.restartPagePipeline(P);
+    pageMod.restartPagePipeline(P);
+  });
+  const stopStore = storeMod.useDesignStore(P, null).subscribe("stations", (stations) => {
+    if (stations?.length) void sectionStore.swapSectionStations(P, R, stations);
+  });
+  pageMod.pipelineEarthwork(P, { conversion: job.conversion });
+  pageMod.restartPagePipeline(P);
+  await quiet();
+  const open = {
+    runs: sliceRuns(0),
+    stations: detail.cross_sections.map((s) => s.chainage_m),
+    final: finalOf(detail),
+    cross: crossOf(detail),
+    same: detail === opened,
+  };
+
+  // 노선 꼭짓점 한 번 끌기 — 상세가 새 노선 측점으로 갈아끼워짐 · 그 횡단을 다시 셈
+  let mark = runs().length;
+  const bridge = pageMod.routeDraftBridge(P, link);
+  bridge.edited(draftOf(shift(1, 6, -4)));
+  await quiet();
+  const cached = await sectionStore.loadSectionDetail(P, R);
+  recompute(cached);
+  const drag = {
+    runs: sliceRuns(mark),
+    swapped: cached !== opened && detail === cached,
+    stations: cached.cross_sections.map((s) => s.chainage_m),
+    final: finalOf(cached),
+  };
+
+  // 되돌리기 한 번(초안 버림)
+  mark = runs().length;
+  const swapMark = swaps.length;
+  bridge.edited(null);
+  await quiet();
+  const back = await sectionStore.loadSectionDetail(P, R);
+  const undo = {
+    runs: sliceRuns(mark),
+    restores,
+    swaps: swaps.length - swapMark,
+    sameObject: back === opened && detail === opened,
+    stations: back.cross_sections.map((s) => s.chainage_m),
+    final: finalOf(back),
+    cross: crossOf(back),
+  };
+  // 되돌린 뒤 조용함 — 더 안 돎
+  mark = runs().length;
+  await quiet();
+  const after = { runs: runs().length - mark, blocked: pageMod.pagePipeline(P).blockedWrites };
+  stopListen();
+  stopStore();
+  pageMod.disposePagePipeline(P);
+  return { open, drag, undo, after };
+}
+
+run()
+  .then((out) => {
+    process.stdout.write(JSON.stringify(out));
+    process.exit(0);
+  })
+  .catch((error) => {
+    process.stderr.write(String(error && error.stack ? error.stack : error));
+    process.exit(1);
+  });
diff --git a/resources/tester/test_349_0k_undo_saved.py b/resources/tester/test_349_0k_undo_saved.py
new file mode 100644
index 000000000..f60a71ec6
--- /dev/null
+++ b/resources/tester/test_349_0k_undo_saved.py
@@ -0,0 +1,131 @@
+"""PLAN 349-0k sub7 — 되돌리기로 저장 노선에 돌아오면 저장 정본 그대로(다시 셈 없음).
+
+· 열기 → 노선 꼭짓점 끌기(상세가 새 노선 측점으로 갈아끼워지고 다시 셈) → 되돌리기 한 번
+· 되돌린 뒤 상세 = 열 때 받은 저장 정본 객체 · 측점 · 횡단 · 누가토량 = 열기 값
+· 되돌리기 = 묶음 한 번 · 더 안 돎
+짝: `helper_349_0k_undo_saved.cjs`(실제 TS 를 Node 로 · 서버 창구만 가짜 · 종단 보기 고리 흉내).
+"""
+
+from __future__ import annotations
+
+import csv
+import json
+import subprocess
+import sys
+import tempfile
+from pathlib import Path
+
+import pytest
+
+HERE = Path(__file__).resolve().parent
+ROOT = HERE.parents[1]
+if str(ROOT) not in sys.path:
+    sys.path.insert(0, str(ROOT))
+
+from B05_Profile.B05_Profile_Structures_Schema import structure_type_map  # noqa: E402
+from common_util.common_util_surface_sampler import dtm_grid_bytes  # noqa: E402
+from config.config_system_design import STANDARD_CROSS_SECTION  # noqa: E402
+
+pytestmark = pytest.mark.skipif(
+    not (ROOT / "config" / "node_modules" / "typescript").is_dir(),
+    reason="프론트엔드 의존성 미설치",
+)
+
+PROJECT = ROOT / "storage/1/3/6d3b2812-6d5a-4168-a932-40e4ae303d5a"  # 검증_sub7
+ROUTE = PROJECT / "B05_Profile/route"
+SECTION = PROJECT / "B06_Section"
+GRID = PROJECT / "B04_PreProcess/models/dtm_classification_smooth.npz"
+ONES = {g: {"loose": 1.0, "compacted": 1.0} for g in ("soil", "ripping_rock", "blasting_rock")}
+
+
+def _csv(path: Path) -> list[list[float]]:
+    with path.open(encoding="utf-8") as handle:
+        return [[float(r["x"]), float(r["y"])] for r in csv.DictReader(handle)]
+
+
+def _json(path: Path):
+    return json.loads(path.read_text(encoding="utf-8"))
+
+
+@pytest.fixture(scope="module")
+def r() -> dict:
+    if not (GRID.is_file() and (SECTION / "longitudinal/longitudinal.json").is_file()):
+        pytest.skip("검증_sub7 없음")
+    curves = _json(ROUTE / "planned_route_curves.json")
+    sections = sorted(
+        (_json(p) for p in (SECTION / "cross_sections").glob("cross_*.json")),
+        key=lambda s: s["chainage_m"],
+    )
+    pipes = _json(PROJECT / "B04_PreProcess/drainage/edits/pipe_points.json")["points"]
+    # 저장 횡단 면적 = 서버가 상세를 낼 때 셈(파일엔 없음) — 정본 대신 정한 값
+    for i, section in enumerate(sections):
+        section["design"] = {
+            "ground_type": "soil",
+            "design_elevation_m": section["center_z"],
+            "cut_area_m2": 4.0 + (i % 5),
+            "fill_area_m2": 1.5 + (i % 3),
+        }
+    job = {
+        "line": _csv(ROUTE / "planned_route.csv"),
+        "nodes": _csv(ROUTE / "planned_route_nodes.csv"),
+        "curves": [
+            {k: c[k] for k in ("start", "apex", "end", "radius_m")} for c in curves["curves"]
+        ],
+        "stationSnap": bool(curves.get("station_snap")),
+        "minRadius": curves["min_radius_m"],
+        "interval": 20.0,
+        "types": [
+            {"type_id": t.type_id, "group": t.group, "placement": t.placement}
+            for t in structure_type_map().values()
+        ],
+        "pipes": pipes,
+        "standard": STANDARD_CROSS_SECTION,
+        "conversion": ONES,
+        "detail": {
+            "longitudinal": _json(SECTION / "longitudinal/longitudinal.json"),
+            "cross_sections": sections,
+        },
+    }
+    with tempfile.TemporaryDirectory() as folder:
+        path = Path(folder) / "job.json"
+        path.write_text(json.dumps(job), encoding="utf-8")
+        grid = Path(folder) / "grid.bin"
+        grid.write_bytes(dtm_grid_bytes(GRID))
+        proc = subprocess.run(  # noqa: S603 — 고정 실행 파일
+            ["node", str(HERE / "helper_349_0k_undo_saved.cjs"), str(path), str(grid)],
+            capture_output=True,
+            text=True,
+            encoding="utf-8",
+            timeout=300,
+        )
+    assert proc.returncode == 0, proc.stderr
+    return json.loads(proc.stdout)
+
+
+def test_열_때_한_번_저장_정본(r):
+    o = r["open"]
+    assert [x["outcome"] for x in o["runs"]] == ["done"], o["runs"]
+    assert o["same"]
+    assert o["final"] is not None
+
+
+def test_끌기_새_측점으로_갈아끼움(r):
+    d = r["drag"]
+    assert [x["sources"] for x in d["runs"]] == [["route"]], d["runs"]
+    assert d["swapped"]  # 이 시험이 갈아끼움 길을 실제로 거침
+    assert d["final"] != r["open"]["final"]
+
+
+def test_되돌리기_열기_값(r):
+    u, o = r["undo"], r["open"]
+    assert [x["sources"] for x in u["runs"]] == [["route"]], u["runs"]
+    assert u["restores"] == [{"saved": True, "back": {"same": True}}]
+    assert u["sameObject"]
+    assert u["stations"] == o["stations"]
+    assert u["cross"] == o["cross"]
+    assert u["final"] == o["final"]
+
+
+def test_되돌린_뒤_조용함(r):
+    assert r["after"]["runs"] == 0
+    assert r["after"]["blocked"] == 0