diff --git a/docs/acceptance/workspace-markdown-preview-20261022/README.md b/docs/acceptance/workspace-markdown-preview-20261022/README.md
new file mode 100644
index 00000000..8dc19b2b
--- /dev/null
+++ b/docs/acceptance/workspace-markdown-preview-20261022/README.md
@@ -0,0 +1,16 @@
+# Workspace Markdown preview
+
+Captured in Chrome at 1440 × 1000 using the production renderer and the `workbenchjourney` production API harness, with its offline model provider and a disposable project. The harness was restarted after rebuilding because it loads the UI bundle at startup.
+
+Both captures open the same 657-byte `preview-notes.md` sample from Workspace files. It contains headings, a list, a table, a fenced code block, an HTTPS link, and a relative file link. Its returned content digest begins with `6d5357a52d91` in both captures.
+
+- **Before** (`5892e371bea0a20596d9684ecd1778049a143700`, PR #442): the file is available only as numbered Markdown source.
+- **After** (this PR): selecting Preview shows formatted content. Source remains the initial view.
+- Searching for `PREVIEW_SEARCH_MARKER` while previewing and clicking its result returned to Source, highlighted line 24, and displayed the position notice.
+- The preview's HTTPS link retained `target="_blank"` and `rel="noreferrer noopener"`; the relative file link rendered as an inert span.
+
+These are unmodified browser screenshots.
+
+![Before: Markdown source only](before-markdown-source.png)
+
+![After: formatted Markdown preview](after-markdown-preview.png)
diff --git a/docs/acceptance/workspace-markdown-preview-20261022/after-markdown-preview.png b/docs/acceptance/workspace-markdown-preview-20261022/after-markdown-preview.png
new file mode 100644
index 00000000..07a8c6b7
Binary files /dev/null and b/docs/acceptance/workspace-markdown-preview-20261022/after-markdown-preview.png differ
diff --git a/docs/acceptance/workspace-markdown-preview-20261022/before-markdown-source.png b/docs/acceptance/workspace-markdown-preview-20261022/before-markdown-source.png
new file mode 100644
index 00000000..dfafbfad
Binary files /dev/null and b/docs/acceptance/workspace-markdown-preview-20261022/before-markdown-source.png differ
diff --git a/docs/acceptance/workspace-search-line-20261022/README.md b/docs/acceptance/workspace-search-line-20261022/README.md
new file mode 100644
index 00000000..247e9d06
--- /dev/null
+++ b/docs/acceptance/workspace-search-line-20261022/README.md
@@ -0,0 +1,14 @@
+# Workspace search line navigation
+
+Captured in Chrome at 1440 × 1000 using the production renderer and the `workbenchjourney` production API harness, with its offline model provider and disposable project.
+
+The temporary project contained a 120-line `search-example.txt`; line 90 contained `SEARCH_HIT_90`. Both captures follow the same interaction: open workspace files, search for the marker, then click its result.
+
+- **Before** (`fc0935d6fc03ca7abccbd148ce52d26c2bc154f8`): the file opened at the top without a highlighted line; the file scroll position was 0.
+- **After** (`0567844fddc33093c61d5093149e8767e39db164`): line 90 was highlighted and visible, with the position notice; the file scroll position was 2702.
+
+These are unmodified browser screenshots. The harness was restarted after rebuilding because it loads the UI bundle at startup.
+
+![Before: search result opens at the top](before-open-hit.png)
+
+![After: search result opens at matching line 90](after-open-hit.png)
diff --git a/docs/acceptance/workspace-search-line-20261022/after-open-hit.png b/docs/acceptance/workspace-search-line-20261022/after-open-hit.png
new file mode 100644
index 00000000..1ac01c22
Binary files /dev/null and b/docs/acceptance/workspace-search-line-20261022/after-open-hit.png differ
diff --git a/docs/acceptance/workspace-search-line-20261022/before-open-hit.png b/docs/acceptance/workspace-search-line-20261022/before-open-hit.png
new file mode 100644
index 00000000..6ac46fa3
Binary files /dev/null and b/docs/acceptance/workspace-search-line-20261022/before-open-hit.png differ
diff --git a/docs/acceptance/workspace-search-retry-20261022/README.md b/docs/acceptance/workspace-search-retry-20261022/README.md
new file mode 100644
index 00000000..ec4b6c85
--- /dev/null
+++ b/docs/acceptance/workspace-search-retry-20261022/README.md
@@ -0,0 +1,12 @@
+# Workspace search retry
+
+Baseline: `b6e89e8c481bb38293d584a9204b36916528c834` (#448).
+
+Both PNGs are unmodified 1440 × 1000 Chrome captures of the production renderer and API served by `cmd/workbenchjourney`. The harness uses a disposable workspace and an offline model; `retry-notes.md` is a temporary document containing `SEARCH_RECOVERY_PROOF`.
+
+For each capture, only the browser's workspace-search requests were temporarily aborted. After the error appeared, the interruption was removed and a direct request confirmed that the real API returned HTTP 200 with the expected file. No API response was replaced.
+
+- `before-retry-stuck.png`: clicking Search again with the unchanged keyword sends no request and leaves the error visible.
+- `after-retry-recovers.png`: the same action sends a request, receives HTTP 200, and displays the result without editing the keyword.
+
+The button and Enter regression cases both fail against the baseline and pass with the fix. The Explorer and Markdown preview suites pass together (21 tests); TypeScript and the production build pass. OCR completed the changed production component with zero findings; its default path rules exclude test files.
diff --git a/docs/acceptance/workspace-search-retry-20261022/after-retry-recovers.png b/docs/acceptance/workspace-search-retry-20261022/after-retry-recovers.png
new file mode 100644
index 00000000..fdccf402
Binary files /dev/null and b/docs/acceptance/workspace-search-retry-20261022/after-retry-recovers.png differ
diff --git a/docs/acceptance/workspace-search-retry-20261022/before-retry-stuck.png b/docs/acceptance/workspace-search-retry-20261022/before-retry-stuck.png
new file mode 100644
index 00000000..dc6cb2f7
Binary files /dev/null and b/docs/acceptance/workspace-search-retry-20261022/before-retry-stuck.png differ
diff --git a/web/src/components/workspace-explorer-preview.test.tsx b/web/src/components/workspace-explorer-preview.test.tsx
new file mode 100644
index 00000000..3ccd25b2
--- /dev/null
+++ b/web/src/components/workspace-explorer-preview.test.tsx
@@ -0,0 +1,152 @@
+import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
+import { render, screen, waitFor, within } from "@testing-library/react";
+import userEvent from "@testing-library/user-event";
+import type { APIClient } from "../api/client";
+import type { WorkspaceExplorerView } from "../api/types";
+import { V2RecoveryProvider } from "../v2/recovery-storage";
+import { FileEditDraftProvider } from "./file-edit-drafts";
+import { WorkspaceExplorer } from "./workspace-explorer";
+
+vi.mock("@monaco-editor/react", () => ({
+  default: ({ value, onChange }: { value: string; onChange: (value: string) => void }) =>
+    <textarea aria-label="Monaco proposal editor" onChange={(event) => onChange(event.target.value)} value={value} />,
+}));
+vi.mock("../lib/monaco-local", () => ({ configureLocalMonaco: vi.fn() }));
+
+describe("WorkspaceExplorer Markdown preview", () => {
+  it("switches the returned content between source and safe formatted Markdown", async () => {
+    const snapshot = markdownSnapshot([
+      "# Project notes", "", "**Ready**", "", "- Review changes", "",
+      "[web](https://example.com/docs) [relative](./notes.md) [local](file:///secret) [unsafe](javascript:alert(1))",
+      "", "![tracking](https://example.com/pixel.png)", "<script>alert(1)</script>",
+      "", "SESSION_SECRET=[REDACTED:secret]",
+    ].join("\n"));
+    const client = previewClient(snapshot);
+    const user = userEvent.setup();
+    const view = renderExplorer(client);
+
+    expect(await screen.findByText("# Project notes")).toBeInTheDocument();
+    expect(screen.getByRole("button", { name: "Source", pressed: true })).toBeInTheDocument();
+    await user.click(screen.getByRole("button", { name: "Preview" }));
+    const preview = screen.getByRole("region", { name: "Markdown preview" });
+    expect(within(preview).getByRole("heading", { name: "Project notes" })).toBeInTheDocument();
+    expect(within(preview).getByText("Ready").tagName).toBe("STRONG");
+    expect(within(preview).getByRole("listitem")).toHaveTextContent("Review changes");
+    expect(within(preview).getByRole("link", { name: "web" })).toHaveAttribute("target", "_blank");
+    expect(within(preview).getByRole("link", { name: "web" })).toHaveAttribute("rel", "noreferrer noopener");
+    for (const label of ["relative", "local", "unsafe"]) {
+      expect(within(preview).getByText(label).tagName).toBe("SPAN");
+    }
+    expect(preview.querySelector("script, img")).not.toBeInTheDocument();
+    expect(preview).toHaveTextContent("SESSION_SECRET=[REDACTED:secret]");
+    expect(screen.getByText("1 redacted")).toBeInTheDocument();
+    expect(view.container.querySelector(".explorer-file-lines")).not.toBeInTheDocument();
+
+    await user.click(screen.getByRole("button", { name: "Source" }));
+    expect(screen.getByText("# Project notes")).toBeInTheDocument();
+    expect(screen.queryByRole("region", { name: "Markdown preview" })).not.toBeInTheDocument();
+    expect(client.workspaceExplore).toHaveBeenCalledTimes(1);
+  });
+
+  it.each(["README.MD", "notes.markdown", "guide.mdown", "notes.txt"])("offers preview only for Markdown paths: %s", async (path) => {
+    const client = previewClient({ ...markdownSnapshot(), path });
+    renderExplorer(client, { initialPath: path });
+    await screen.findByText("# Project notes");
+    expect(Boolean(screen.queryByRole("button", { name: "Preview" }))).toBe(path !== "notes.txt");
+  });
+
+  it("returns to source for search results and later citation lines", async () => {
+    const client = previewClient(markdownSnapshot());
+    const user = userEvent.setup();
+    const queryClient = new QueryClient({ defaultOptions: { queries: { retry: false } } });
+    const explorer = (initialLine: number) => <QueryClientProvider client={queryClient}>
+      <WorkspaceExplorer client={client} workspaceID="workspace-1" initialPath="README.md" initialLine={initialLine} />
+    </QueryClientProvider>;
+    const view = render(explorer(1));
+    await user.click(await screen.findByRole("button", { name: "Preview" }));
+    expect(screen.queryByText("Positioned at line 1")).not.toBeInTheDocument();
+    await user.type(screen.getByLabelText("Search Workspace evidence"), "matched");
+    await user.click(screen.getByRole("button", { name: "Search Workspace" }));
+    await user.click(await screen.findByRole("button", { name: /README.md.*line 2/ }));
+    expect(await screen.findByText("Positioned at line 2")).toBeInTheDocument();
+    expect(screen.getByRole("button", { name: "Source", pressed: true })).toBeInTheDocument();
+    expect(view.container.querySelector('[data-line="2"]')).toHaveClass("is-highlighted");
+
+    await user.click(screen.getByRole("button", { name: "Preview" }));
+    view.rerender(explorer(3));
+    expect(await screen.findByText("Positioned at line 3")).toBeInTheDocument();
+    expect(screen.getByRole("button", { name: "Source", pressed: true })).toBeInTheDocument();
+  });
+
+  it("references the same snapshot and retains truncation and provenance in preview", async () => {
+    const snapshot = { ...markdownSnapshot(), truncated: true, total_bytes: 1024 };
+    const onSelectReference = vi.fn();
+    const client = previewClient(snapshot);
+    const user = userEvent.setup();
+    renderExplorer(client, { onSelectReference });
+    await user.click(await screen.findByRole("button", { name: "Reference this file" }));
+    await user.click(screen.getByRole("button", { name: "Preview" }));
+    await user.click(screen.getByRole("button", { name: "Reference this file" }));
+    expect(onSelectReference.mock.calls).toEqual([[snapshot], [snapshot]]);
+    expect(screen.getByText("truncated")).toBeInTheDocument();
+    expect(screen.getByText("workspace_file / File source record")).toBeInTheDocument();
+    expect(screen.getByText("b".repeat(12))).toBeInTheDocument();
+    expect(client.workspaceExplore).toHaveBeenCalledTimes(1);
+  });
+
+  it("keeps an editing draft across returning to preview and switching views", async () => {
+    const snapshot = { ...markdownSnapshot(), redaction_count: 0 };
+    const client = Object.assign(previewClient(snapshot), {
+      hasFileEditProposals: true,
+      issueFileEditProposalSource: vi.fn().mockResolvedValue({
+        protocol_version: "file_edit_proposal.v1", run_id: "run-1", workspace_id: "workspace-1",
+        path: snapshot.path, content: snapshot.content, content_sha256: snapshot.provenance.content_sha256,
+        source_handle: "B".repeat(43), expires_at: "2099-07-18T00:05:00Z", editable: true, file_write: false,
+      }),
+      createFileEditProposal: vi.fn(),
+    });
+    const user = userEvent.setup();
+    renderExplorer(client, { runID: "run-1" });
+    await user.click(await screen.findByRole("button", { name: "Preview" }));
+    await user.click(screen.getByRole("button", { name: "Edit proposal" }));
+    const editor = await screen.findByLabelText("Monaco proposal editor");
+    expect(screen.queryByRole("group", { name: "File view" })).not.toBeInTheDocument();
+    await user.clear(editor);
+    await user.type(editor, "# Retained draft");
+    await user.click(screen.getByRole("button", { name: "Close file proposal editor" }));
+    await user.click(screen.getByRole("button", { name: "Keep draft" }));
+    expect(screen.getByRole("region", { name: "Markdown preview" })).toBeInTheDocument();
+    await user.click(screen.getByRole("button", { name: "Source" }));
+    await user.click(screen.getByRole("button", { name: "Preview" }));
+    await user.click(screen.getByRole("button", { name: "Edit proposal" }));
+    await waitFor(() => expect(screen.getByLabelText("Monaco proposal editor")).toHaveValue("# Retained draft"));
+    expect(client.createFileEditProposal).not.toHaveBeenCalled();
+  });
+});
+
+function markdownSnapshot(content = "# Project notes\nmatched text\nthird line\n"): WorkspaceExplorerView {
+  return {
+    protocol_version: "workspace_explorer.v1", workspace_id: "workspace-1", path: "README.md",
+    kind: "file", entries: [], content, total_bytes: content.length, returned_bytes: content.length,
+    truncated: false, redaction_count: 1, root_path_exposed: false,
+    provenance: { version: "context_provenance.v1", source_kind: "workspace_file", source_ref: "README.md",
+      content_sha256: "b".repeat(64), instruction_authorized: false },
+  };
+}
+
+function previewClient(snapshot: WorkspaceExplorerView) {
+  return Object.assign({} as APIClient, {
+    baseURL: "http://localhost:8765/api/v1",
+    workspaceExplore: vi.fn().mockResolvedValue(snapshot),
+    workspaceSearch: vi.fn().mockResolvedValue({ results: [{ path: "README.md", line: 2,
+      match_kind: "content", snippet: "matched text", content_truncated: false,
+      provenance: snapshot.provenance }], truncated: false }),
+  });
+}
+
+function renderExplorer(client: APIClient, props: Partial<Parameters<typeof WorkspaceExplorer>[0]> = {}) {
+  const queryClient = new QueryClient({ defaultOptions: { queries: { retry: false } } });
+  return render(<QueryClientProvider client={queryClient}><V2RecoveryProvider client={client} scopeID="preview-tests"><FileEditDraftProvider>
+    <WorkspaceExplorer client={client} workspaceID="workspace-1" initialPath="README.md" {...props} />
+  </FileEditDraftProvider></V2RecoveryProvider></QueryClientProvider>);
+}
diff --git a/web/src/components/workspace-explorer.css b/web/src/components/workspace-explorer.css
new file mode 100644
index 00000000..bf3b2be2
--- /dev/null
+++ b/web/src/components/workspace-explorer.css
@@ -0,0 +1,34 @@
+.explorer-file > .explorer-file-summary {
+  flex-wrap: wrap;
+  padding: 6px 0;
+}
+
+.explorer-view-switch {
+  display: flex;
+  gap: 4px;
+  margin-right: auto;
+}
+
+.explorer-view-switch .compact-command[aria-pressed="true"] {
+  background: var(--prayu-control);
+  color: var(--prayu-text);
+  font-weight: 600;
+}
+
+.explorer-markdown-preview {
+  max-height: calc(100vh - 280px);
+  min-height: 280px;
+  padding: 16px;
+  overflow: auto;
+  border: 1px solid var(--border);
+  border-radius: 5px;
+  background: var(--prayu-surface-solid);
+  color: var(--prayu-text);
+  font-size: 13px;
+  line-height: 1.6;
+}
+
+.explorer-markdown-preview .safe-markdown pre {
+  min-height: 0;
+  max-height: none;
+}
diff --git a/web/src/components/workspace-explorer.test.tsx b/web/src/components/workspace-explorer.test.tsx
index 29c1afec..26a4cb1d 100644
--- a/web/src/components/workspace-explorer.test.tsx
+++ b/web/src/components/workspace-explorer.test.tsx
@@ -1,7 +1,9 @@
 import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
+import { useState } from "react";
 import { render, screen, waitFor } from "@testing-library/react";
 import userEvent from "@testing-library/user-event";
 import type { APIClient } from "../api/client";
+import { FileEditDraftProvider, useFileEditLeaveEntry } from "./file-edit-drafts";
 import { WorkspaceExplorer } from "./workspace-explorer";
 
 describe("WorkspaceExplorer", () => {
@@ -79,6 +81,30 @@ describe("WorkspaceExplorer", () => {
     expect(line2).toHaveClass("is-highlighted");
   });
 
+  it.each(["button", "Enter"])("retries a failed search with the unchanged query using %s", async (submit) => {
+    const client = searchableClient();
+    client.workspaceSearch.mockRejectedValueOnce(new Error("Search temporarily unavailable"));
+    const user = userEvent.setup();
+    renderExplorer(client);
+
+    await searchFor(user, "automated");
+    expect(await screen.findByRole("alert")).toHaveTextContent("Search temporarily unavailable");
+    expect(client.workspaceSearch).toHaveBeenCalledTimes(1);
+    const input = screen.getByLabelText("Search Workspace evidence");
+    if (submit === "Enter") {
+      await user.click(input);
+      await user.keyboard("{Enter}");
+    } else {
+      await user.click(screen.getByRole("button", { name: "Search Workspace" }));
+    }
+
+    expect(await screen.findByRole("button", { name: /README.md.*line 2/ })).toBeInTheDocument();
+    expect(input).toHaveValue("automated");
+    expect(screen.queryByRole("alert")).not.toBeInTheDocument();
+    expect(client.workspaceSearch).toHaveBeenCalledTimes(2);
+    expect(client.workspaceSearch).toHaveBeenLastCalledWith("workspace-1", "automated", expect.any(AbortSignal));
+  });
+
   it("warns when requested line exceeds the visible lines", async () => {
     const workspaceExplore = vi.fn().mockResolvedValue(fileSnapshot());
     const client = { workspaceExplore } as unknown as APIClient;
@@ -91,8 +117,138 @@ describe("WorkspaceExplorer", () => {
 
     expect(await screen.findByRole("alert")).toHaveTextContent(/out of loaded range|超出当前显示范围/);
   });
+
+  it.each([
+    { name: "without a parent callback", mirrored: false, initialPath: ".", initialLine: undefined },
+    { name: "when the parent mirrors a new path", mirrored: true, initialPath: ".", initialLine: undefined },
+    { name: "when the parent clears the same file's citation line", mirrored: true, initialPath: "README.md", initialLine: 1 },
+  ])("opens a search result at its matching line $name", async ({ mirrored, initialPath, initialLine }) => {
+    const client = searchableClient();
+    const user = userEvent.setup();
+    const queryClient = new QueryClient({ defaultOptions: { queries: { retry: false } } });
+    const view = render(<QueryClientProvider client={queryClient}>
+      {mirrored ? <MirroredExplorer client={client} initialPath={initialPath} initialLine={initialLine} /> :
+        <WorkspaceExplorer client={client} workspaceID="workspace-1" />}
+    </QueryClientProvider>);
+
+    await searchFor(user, "automated");
+    await user.click(await screen.findByRole("button", { name: /README.md.*line 2/ }));
+
+    expect(await screen.findByText("Positioned at line 2")).toBeInTheDocument();
+    expect(view.container.querySelector('[data-line="2"]')).toHaveClass("is-highlighted");
+    expect(client.workspaceExplore).toHaveBeenLastCalledWith("workspace-1", "README.md", expect.any(AbortSignal));
+  });
+
+  it("clears a previous hit for filename results and ordinary directory navigation", async () => {
+    const client = searchableClient();
+    const user = userEvent.setup();
+    const view = renderExplorer(client);
+    await searchFor(user, "automated");
+    await user.click(await screen.findByRole("button", { name: /README.md.*line 2/ }));
+    expect(await screen.findByText("Positioned at line 2")).toBeInTheDocument();
+
+    client.workspaceSearch.mockResolvedValueOnce(searchSnapshot(0));
+    await searchFor(user, "readme");
+    await user.click(await screen.findByRole("button", { name: /README.md.*filename/ }));
+    expect(view.container.querySelector(".is-highlighted")).not.toBeInTheDocument();
+    expect(screen.queryByText(/Positioned at line/)).not.toBeInTheDocument();
+
+    await searchFor(user, "automated");
+    await user.click(await screen.findByRole("button", { name: /README.md.*line 2/ }));
+    expect(await screen.findByText("Positioned at line 2")).toBeInTheDocument();
+    await user.click(screen.getByRole("button", { name: "Open parent directory" }));
+    await user.click(screen.getByRole("button", { name: "Close search results" }));
+    await user.click(await screen.findByRole("button", { name: /README.md/ }));
+    expect(view.container.querySelector(".is-highlighted")).not.toBeInTheDocument();
+  });
+
+  it("scrolls back to the matching line when the same result is selected again", async () => {
+    const client = searchableClient();
+    const user = userEvent.setup();
+    const view = renderExplorer(client);
+    await searchFor(user, "automated");
+    await user.click(await screen.findByRole("button", { name: /README.md.*line 2/ }));
+    expect(await screen.findByText("Positioned at line 2")).toBeInTheDocument();
+    const line = view.container.querySelector('[data-line="2"]')!;
+    const scroll = vi.fn();
+    Object.defineProperty(line, "scrollIntoView", { value: scroll });
+    await user.click(screen.getByRole("button", { name: /README.md.*line 2/ }));
+    expect(scroll).toHaveBeenCalledWith({ block: "center", behavior: "smooth" });
+  });
+
+  it("honors a later external location and resets the hit when the workspace or run changes", async () => {
+    const client = searchableClient();
+    const user = userEvent.setup();
+    const queryClient = new QueryClient({ defaultOptions: { queries: { retry: false } } });
+    const explorer = (workspaceID: string, runID: string, initialLine?: number) =>
+      <QueryClientProvider client={queryClient}><WorkspaceExplorer client={client}
+        workspaceID={workspaceID} runID={runID} initialPath="README.md" initialLine={initialLine} /></QueryClientProvider>;
+    const view = render(explorer("workspace-1", "run-1"));
+    await searchFor(user, "automated");
+    await user.click(await screen.findByRole("button", { name: /README.md.*line 2/ }));
+    expect(await screen.findByText("Positioned at line 2")).toBeInTheDocument();
+    view.rerender(explorer("workspace-1", "run-1", 1));
+    expect(await screen.findByText("Positioned at line 1")).toBeInTheDocument();
+    view.rerender(explorer("workspace-2", "run-2"));
+    await waitFor(() => expect(client.workspaceExplore).toHaveBeenLastCalledWith("workspace-2", "README.md", expect.any(AbortSignal)));
+    expect(view.container.querySelector(".is-highlighted")).not.toBeInTheDocument();
+  });
+
+  it("changes neither file nor line until unsaved edits allow the search navigation", async () => {
+    const client = searchableClient();
+    client.workspaceSearch.mockResolvedValue(searchSnapshot(2, "notes.txt"));
+    const user = userEvent.setup();
+    const queryClient = new QueryClient({ defaultOptions: { queries: { retry: false } } });
+    render(<QueryClientProvider client={queryClient}><FileEditDraftProvider>
+      <UnsavedFile />
+      <WorkspaceExplorer client={client} workspaceID="workspace-1" initialPath="README.md" initialLine={1} />
+    </FileEditDraftProvider></QueryClientProvider>);
+    await searchFor(user, "automated");
+    await user.click(await screen.findByRole("button", { name: /notes.txt.*line 2/ }));
+    await user.click(screen.getByRole("button", { name: "Continue editing" }));
+    expect(screen.getByText("Positioned at line 1")).toBeInTheDocument();
+    expect(client.workspaceExplore).toHaveBeenCalledTimes(1);
+    await user.click(screen.getByRole("button", { name: /notes.txt.*line 2/ }));
+    await user.click(screen.getByRole("button", { name: "Keep draft" }));
+    expect(await screen.findByText("Positioned at line 2")).toBeInTheDocument();
+    expect(client.workspaceExplore).toHaveBeenLastCalledWith("workspace-1", "notes.txt", expect.any(AbortSignal));
+  });
 });
 
+function MirroredExplorer({ client, initialPath, initialLine }: {
+  client: APIClient; initialPath: string; initialLine?: number;
+}) {
+  const [location, setLocation] = useState({ path: initialPath, line: initialLine });
+  return <WorkspaceExplorer client={client} workspaceID="workspace-1" initialPath={location.path}
+    initialLine={location.line} onPathChange={(path) => setLocation({ path, line: undefined })} />;
+}
+
+function UnsavedFile() {
+  useFileEditLeaveEntry({ path: "README.md", dirty: true, busy: false, canSave: false,
+    save: async () => {}, keep: () => {}, discard: () => {} });
+  return null;
+}
+
+function searchableClient() {
+  return Object.assign({} as APIClient, {
+    workspaceExplore: vi.fn(async (_workspaceID: string, path = ".") => path === "." ? directorySnapshot() :
+      { ...fileSnapshot(), path }),
+    workspaceSearch: vi.fn().mockResolvedValue(searchSnapshot()),
+  });
+}
+
+function searchSnapshot(line = 2, path = "README.md") {
+  return { results: [{ path, line, match_kind: line ? "content" : "filename", snippet: "",
+    content_truncated: false, provenance: fileSnapshot().provenance }], truncated: false };
+}
+
+async function searchFor(user: ReturnType<typeof userEvent.setup>, query: string) {
+  const input = await screen.findByLabelText("Search Workspace evidence");
+  await user.clear(input);
+  await user.type(input, query);
+  await user.click(screen.getByRole("button", { name: "Search Workspace" }));
+}
+
 function directorySnapshot() {
   return {
     protocol_version: "workspace_explorer.v1", workspace_id: "workspace-1", path: ".",
diff --git a/web/src/components/workspace-explorer.tsx b/web/src/components/workspace-explorer.tsx
index d1671f27..767aab9f 100644
--- a/web/src/components/workspace-explorer.tsx
+++ b/web/src/components/workspace-explorer.tsx
@@ -8,6 +8,8 @@ import { useLocale } from "../lib/locale";
 import { EmptyState, ErrorState, LoadingState, StatusBadge } from "./common";
 import { FileProposalEditor } from "./file-proposal-editor";
 import { useFileEditLeave } from "./file-edit-drafts";
+import { SafeMarkdown } from "./safe-markdown";
+import "./workspace-explorer.css";
 
 export function WorkspaceExplorer({ client, workspaceID, runID = "", initialPath = ".", initialLine, onSelectReference, onPathChange }: {
   client: APIClient;
@@ -20,15 +22,23 @@ export function WorkspaceExplorer({ client, workspaceID, runID = "", initialPath
 }) {
   const { t } = useLocale();
   const leave = useFileEditLeave();
-  const [path, setPath] = useState(initialPath);
-  const [highlightLine, setHighlightLine] = useState<number | undefined>(initialLine);
+  const [location, setLocation] = useState({ path: initialPath, line: initialLine, view: "source" as "source" | "preview" });
+  const { path, line: highlightLine } = location;
   const highlightedLineRef = useRef<HTMLDivElement>(null);
   const [searchInput, setSearchInput] = useState("");
   const [searchQuery, setSearchQuery] = useState("");
   const operationKeys = useRef(new Map<string, string>());
+  const reportedNavigation = useRef<{ workspaceID: string; runID: string; path: string } | undefined>(undefined);
   useEffect(() => {
-    setPath(initialPath);
-    setHighlightLine(initialLine);
+    const reported = reportedNavigation.current;
+    // Parents can mirror onPathChange while clearing the previous citation line.
+    // That acknowledgment must not replace the line selected by a search result.
+    const isNavigationEcho = reported?.workspaceID === workspaceID && reported.runID === runID &&
+      reported.path === initialPath && initialLine === undefined;
+    reportedNavigation.current = undefined;
+    if (!isNavigationEcho) {
+      setLocation({ path: initialPath, line: initialLine, view: "source" });
+    }
     setSearchInput("");
     setSearchQuery("");
     operationKeys.current.clear();
@@ -43,7 +53,7 @@ export function WorkspaceExplorer({ client, workspaceID, runID = "", initialPath
     if (highlightLine && highlightedLineRef.current) {
       highlightedLineRef.current.scrollIntoView?.({ block: "center", behavior: "smooth" });
     }
-  }, [highlightLine, path, query.data]);
+  }, [location, query.data]);
   const search = useQuery({
     queryKey: ["workspace", workspaceID, "search", searchQuery],
     queryFn: ({ signal }) => client.workspaceSearch(workspaceID, searchQuery, signal),
@@ -64,9 +74,11 @@ export function WorkspaceExplorer({ client, workspaceID, runID = "", initialPath
     mutationFn: (sourcePath: string) => client.issueFileEditProposalSource(runID, sourcePath),
   });
   const parent = useMemo(() => parentPath(path), [path]);
-  const navigate = (nextPath: string) => leave(() => {
+  const navigate = (nextPath: string, nextLine?: number) => leave(() => {
     proposalSource.reset();
-    setPath(nextPath);
+    setLocation({ path: nextPath, line: nextLine, view: "source" });
+    reportedNavigation.current = onPathChange && (nextPath !== initialPath || initialLine !== undefined)
+      ? { workspaceID, runID, path: nextPath } : undefined;
     onPathChange?.(nextPath);
   });
 
@@ -74,7 +86,11 @@ export function WorkspaceExplorer({ client, workspaceID, runID = "", initialPath
     event.preventDefault();
     const normalized = searchInput.trim();
     if (normalized && normalized === searchInput && normalized.length <= 128) {
-      setSearchQuery(normalized);
+      if (normalized === searchQuery && search.isError) {
+        void search.refetch();
+      } else {
+        setSearchQuery(normalized);
+      }
     }
   };
 
@@ -176,22 +192,32 @@ export function WorkspaceExplorer({ client, workspaceID, runID = "", initialPath
       <FileProposalEditor client={client} onClose={() => proposalSource.reset()}
         runID={runID} source={proposalSource.data} /> :
     snapshot.kind === "file" && (() => {
+      const isMarkdown = /\.(md|markdown|mdown)$/iu.test(snapshot.path);
+      const showPreview = isMarkdown && location.view === "preview";
       const lines = snapshot.content.split("\n");
       const lineOutOfRange = highlightLine !== undefined && (highlightLine < 1 || highlightLine > lines.length);
       const lineHighlighted = highlightLine !== undefined && highlightLine >= 1 && highlightLine <= lines.length;
       return <div className="explorer-file">
-        <div>
+        <div className="explorer-file-summary">
+          {isMarkdown && <div className="explorer-view-switch" role="group" aria-label={t("文件视图", "File view")}>
+            <button aria-pressed={!showPreview} className="compact-command" type="button"
+              onClick={() => setLocation((current) => ({ ...current, view: "source" }))}>{t("源码", "Source")}</button>
+            <button aria-pressed={showPreview} className="compact-command" type="button"
+              onClick={() => setLocation((current) => ({ ...current, view: "preview" }))}>{t("预览", "Preview")}</button>
+          </div>}
           <span>{t(`已显示 ${formatBytes(snapshot.returned_bytes)}`, `${formatBytes(snapshot.returned_bytes)} shown`)}</span>
           <span>{t(`共 ${formatBytes(snapshot.total_bytes)}`, `${formatBytes(snapshot.total_bytes)} total`)}</span>
         </div>
-        {lineOutOfRange && <div className="explorer-line-warning" role="alert">
+        {!showPreview && lineOutOfRange && <div className="explorer-line-warning" role="alert">
           {t(`定位到第 ${highlightLine} 行失败：超出当前显示范围（已显示 ${lines.length} 行${snapshot.truncated ? "，文件已截断" : ""}）`,
             `Failed to position line ${highlightLine}: out of loaded range (${lines.length} lines shown${snapshot.truncated ? ", truncated" : ""})`)}
         </div>}
-        {lineHighlighted && <div className="explorer-line-notice" role="status">
+        {!showPreview && lineHighlighted && <div className="explorer-line-notice" role="status">
           {t(`已定位到第 ${highlightLine} 行`, `Positioned at line ${highlightLine}`)}
         </div>}
-        <div className="explorer-file-lines">
+        {showPreview ? <section className="explorer-markdown-preview" aria-label={t("Markdown 预览", "Markdown preview")}>
+          <SafeMarkdown>{snapshot.content}</SafeMarkdown>
+        </section> : <div className="explorer-file-lines">
           {lines.map((lineContent, index) => {
             const lineNum = index + 1;
             const isHighlight = lineNum === highlightLine;
@@ -201,7 +227,7 @@ export function WorkspaceExplorer({ client, workspaceID, runID = "", initialPath
               <span className="explorer-line-content">{lineContent}</span>
             </div>;
           })}
-        </div>
+        </div>}
       </div>;
     })()}
   </section>;
@@ -214,7 +240,7 @@ function WorkspaceSearchResults({ client, runID, pending, query, onAttach, onCle
   query: UseQueryResult<WorkspaceSearchView, Error>;
   onAttach: (path: string, digest: string) => void;
   onClear: () => void;
-  onOpen: (path: string) => void;
+  onOpen: (path: string, line?: number) => void;
 }) {
   const { t } = useLocale();
   if (query.isLoading) return <LoadingState label={t("正在搜索工作区", "Searching Workspace")} />;
@@ -228,7 +254,7 @@ function WorkspaceSearchResults({ client, runID, pending, query, onAttach, onCle
     </header>
     {data.results.length === 0 && <EmptyState>{t("没有匹配的证据", "No matching evidence")}</EmptyState>}
     {data.results.map((result) => <div className="explorer-search-result" key={result.path}>
-      <button className="search-result-open" onClick={() => onOpen(result.path)} type="button">
+      <button className="search-result-open" onClick={() => onOpen(result.path, result.line > 0 ? result.line : undefined)} type="button">
         <File aria-hidden="true" size={15} />
         <span><strong>{result.path}</strong>
           <small>{result.line > 0 ? t(`第 ${result.line} 行`, `line ${result.line}`) : result.match_kind}</small>