diff --git a/src/features/tech-log/presentation/public/components/home-focus.tsx b/src/features/tech-log/presentation/public/components/home-focus.tsx
index 50e7e34..ce81ab4 100644
--- a/src/features/tech-log/presentation/public/components/home-focus.tsx
+++ b/src/features/tech-log/presentation/public/components/home-focus.tsx
@@ -1,4 +1,4 @@
-import { useEffect, useRef, useState } from "react";
+import { useCallback, useEffect, useRef, useState } from "react";
 import { Link, useLocation, useNavigate } from "react-router-dom";
 
 import type {
@@ -28,23 +28,30 @@ export function HomeFocus({
   const keys = items.map((item) => item.key);
   const activeItem = items.find((item) => item.key === activeKey) ?? items[0];
 
-  function replaceFocus(key: FocusKey) {
-    const search = new URLSearchParams(location.search);
-    search.set("focus", key);
-    void navigate(
-      {
-        pathname: location.pathname,
-        search: `?${search.toString()}`,
-        hash: location.hash,
-      },
-      { replace: true },
-    );
-  }
+  const replaceFocus = useCallback(
+    (key: FocusKey) => {
+      const search = new URLSearchParams(location.search);
+      search.set("focus", key);
+      void navigate(
+        {
+          pathname: location.pathname,
+          search: `?${search.toString()}`,
+          hash: location.hash,
+        },
+        { replace: true },
+      );
+    },
+    [location.hash, location.pathname, location.search, navigate],
+  );
 
   useEffect(() => {
-    if (!shouldNormalizeFocusUrl(requestedKey, activeKey)) return;
-    replaceFocus(activeKey);
-  });
+    setActiveKey(initialKey);
+  }, [initialKey]);
+
+  useEffect(() => {
+    if (!shouldNormalizeFocusUrl(requestedKey, initialKey)) return;
+    replaceFocus(initialKey);
+  }, [initialKey, replaceFocus, requestedKey]);
 
   function select(key: FocusKey, moveKeyboardFocus = false) {
     setActiveKey(key);
diff --git a/src/presentation/routes/app-router.tsx b/src/presentation/routes/app-router.tsx
index a0c854e..01873b0 100644
--- a/src/presentation/routes/app-router.tsx
+++ b/src/presentation/routes/app-router.tsx
@@ -50,6 +50,7 @@ import {
 import type { ParsedRouteInput } from "./route-contract.ts";
 import {
   RegisteredNotFoundProvider,
+  type RegisteredNotFoundDescriptor,
   RouteInputProvider,
 } from "./route-input.tsx";
 
@@ -259,14 +260,14 @@ function RegisteredRoute<RouteIdValue extends string>({
   definition,
   runtime,
   codecs,
-  NotFoundComponent,
+  registeredNotFound,
 }: {
   routeId: RouteIdValue;
   buildId: string;
   definition: RouteDefinition;
   runtime: GroupedRouteRuntimeDefinition;
   codecs: RouteCodecRegistry;
-  NotFoundComponent?: ComponentType;
+  registeredNotFound?: RegisteredNotFoundRegistration;
 }) {
   const params = useParams();
   const [search] = useSearchParams();
@@ -282,10 +283,35 @@ function RegisteredRoute<RouteIdValue extends string>({
   if (!parsed.success) return <InvalidRouteSurface code={parsed.code} />;
   const routeInput = parsed.data;
   const RuntimeComponent = runtime.Component;
+  const notFoundDescriptor: RegisteredNotFoundDescriptor | undefined =
+    registeredNotFound
+      ? {
+          ...registeredNotFound,
+          render: () => {
+            const NotFoundRuntime = registeredNotFound.runtime.Component;
+            return (
+              <Suspense
+                fallback={
+                  <RouteLoadingSurface
+                    definition={registeredNotFound.definition}
+                  />
+                }
+              >
+                <ChunkRecoveryBoundary
+                  chunkId={registeredNotFound.definition.chunkId}
+                  recover={recovery.recoverChunk}
+                >
+                  <NotFoundRuntime />
+                </ChunkRecoveryBoundary>
+              </Suspense>
+            );
+          },
+        }
+      : undefined;
 
   const content = (
     <RouteInputProvider input={routeInput}>
-      <RegisteredNotFoundProvider Component={NotFoundComponent}>
+      <RegisteredNotFoundProvider descriptor={notFoundDescriptor}>
         <CanonicalRouteRedirect
           input={routeInput}
           definition={definition}
@@ -329,6 +355,12 @@ type GroupedRouteRuntimeDefinition = Readonly<{
   Component: ComponentType;
 }>;
 
+type RegisteredNotFoundRegistration = Readonly<{
+  definition: RouteDefinition;
+  runtime: GroupedRouteRuntimeDefinition;
+  buildId: string;
+}>;
+
 type GroupedRouteRegistry = Readonly<Record<string, RouteDefinition>>;
 type GroupedRouteRuntime = Readonly<
   Record<string, GroupedRouteRuntimeDefinition>
@@ -352,7 +384,16 @@ export function createGroupedRouteObjects(
     PUBLIC: [],
     STUDIO: [],
   };
-  const NotFoundComponent = runtime.NOT_FOUND?.Component;
+  const notFoundDefinition = registry.NOT_FOUND;
+  const notFoundRuntime = runtime.NOT_FOUND;
+  const registeredNotFound =
+    notFoundDefinition && notFoundRuntime
+      ? {
+          definition: notFoundDefinition,
+          runtime: notFoundRuntime,
+          buildId,
+        }
+      : undefined;
   for (const definition of Object.values(registry)) {
     const routeId = definition.routeId;
     const routeRuntime = runtime[definition.routeId];
@@ -366,7 +407,11 @@ export function createGroupedRouteObjects(
         definition={definition}
         runtime={routeRuntime}
         codecs={codecs}
-        NotFoundComponent={NotFoundComponent}
+        registeredNotFound={
+          definition.layoutGroup === notFoundDefinition?.layoutGroup
+            ? registeredNotFound
+            : undefined
+        }
       />
     );
     if (definition.path === "/") {
diff --git a/src/presentation/routes/route-input.tsx b/src/presentation/routes/route-input.tsx
index a14d240..7bd0b07 100644
--- a/src/presentation/routes/route-input.tsx
+++ b/src/presentation/routes/route-input.tsx
@@ -5,10 +5,23 @@ import {
   useContext,
 } from "react";
 
+import type { RouteDefinition } from "../../contracts/routes.ts";
 import type { ParsedRouteInput, RouteId } from "./route-contract.ts";
 
 const RouteInputContext = createContext<ParsedRouteInput<string> | null>(null);
-const RegisteredNotFoundContext = createContext<ComponentType | null>(null);
+
+export type RegisteredNotFoundDescriptor = Readonly<{
+  definition: RouteDefinition;
+  runtime: Readonly<{
+    moduleId: string;
+    Component: ComponentType;
+  }>;
+  buildId: string;
+  render(): ReactNode;
+}>;
+
+const RegisteredNotFoundContext =
+  createContext<RegisteredNotFoundDescriptor | null>(null);
 
 export function RouteInputProvider<RouteIdValue extends string>({
   input,
@@ -33,21 +46,23 @@ export function useRouteInput<
 }
 
 export function RegisteredNotFoundProvider({
-  Component,
+  descriptor,
   children,
 }: Readonly<{
-  Component?: ComponentType;
+  descriptor?: RegisteredNotFoundDescriptor;
   children: ReactNode;
 }>) {
   return (
-    <RegisteredNotFoundContext.Provider value={Component ?? null}>
+    <RegisteredNotFoundContext.Provider value={descriptor ?? null}>
       {children}
     </RegisteredNotFoundContext.Provider>
   );
 }
 
 export function RegisteredNotFoundRoute() {
-  const Component = useContext(RegisteredNotFoundContext);
-  if (!Component) throw new Error("Registered not-found runtime is required");
-  return <Component />;
+  const descriptor = useContext(RegisteredNotFoundContext);
+  if (!descriptor) {
+    throw new Error("Registered not-found runtime is required");
+  }
+  return descriptor.render();
 }
diff --git a/tests/features/tech-log/public-discovery-screens.test.tsx b/tests/features/tech-log/public-discovery-screens.test.tsx
index acb704e..25f39e0 100644
--- a/tests/features/tech-log/public-discovery-screens.test.tsx
+++ b/tests/features/tech-log/public-discovery-screens.test.tsx
@@ -1,8 +1,9 @@
 // @vitest-environment jsdom
 
-import { render, screen, waitFor, within } from "@testing-library/react";
+import { act, render, screen, waitFor, within } from "@testing-library/react";
 import userEvent from "@testing-library/user-event";
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import { lazy, type ComponentType } from "react";
 import {
   createMemoryRouter,
   Outlet,
@@ -47,9 +48,15 @@ const routeComponents = {
 
 type DiscoveryRouteId = keyof typeof routeComponents;
 
+type DiscoveryRenderOptions = Readonly<{
+  NotFoundComponent?: ComponentType;
+  application?: ReturnType<typeof createTestApplication>;
+}>;
+
 function renderDiscoveryRoute<RouteId extends DiscoveryRouteId>(
   routeId: RouteId,
   initialEntry: string,
+  options: DiscoveryRenderOptions = {},
 ) {
   const definition = TECH_LOG_ROUTE_REGISTRY[routeId];
   const runtime = TECH_LOG_ROUTE_RUNTIME_CONTRACT[routeId];
@@ -67,7 +74,7 @@ function renderDiscoveryRoute<RouteId extends DiscoveryRouteId>(
         },
         NOT_FOUND: {
           moduleId: TECH_LOG_ROUTE_RUNTIME_CONTRACT.NOT_FOUND.moduleId,
-          Component: NotFoundPage,
+          Component: options.NotFoundComponent ?? NotFoundPage,
         },
       },
       {
@@ -86,9 +93,12 @@ function renderDiscoveryRoute<RouteId extends DiscoveryRouteId>(
   const techLog = createTechLogFeatureInstalledInput().input;
   const view = render(
     <ApplicationProvider
-      application={createTestApplication({
-        featureInputs: { "tech-log": techLog },
-      })}
+      application={
+        options.application ??
+        createTestApplication({
+          featureInputs: { "tech-log": techLog },
+        })
+      }
     >
       <RouterProvider router={router} />
     </ApplicationProvider>,
@@ -183,6 +193,62 @@ describe("TechLog home discovery", () => {
     expect(screen.getAllByRole("tabpanel")).toHaveLength(1);
   });
 
+  it("treats external focus URL changes as authoritative without stealing focus", async () => {
+    const { router } = renderDiscoveryRoute(
+      "TECH_LOG_HOME",
+      "/?focus=current&state=latest-empty#latest",
+    );
+    const current = screen.getByRole("tab", { name: "현재 작업" });
+    current.focus();
+
+    await router.navigate("/?focus=question&state=latest-empty#latest");
+
+    await waitFor(() => {
+      expect(screen.getByRole("tab", { name: "열린 질문" })).toHaveAttribute(
+        "aria-selected",
+        "true",
+      );
+    });
+    expect(router.state.location).toMatchObject({
+      pathname: "/",
+      search: "?focus=question&state=latest-empty",
+      hash: "#latest",
+    });
+    expect(screen.getByRole("tab", { name: "열린 질문" })).toHaveAttribute(
+      "tabindex",
+      "0",
+    );
+    expect(current).toHaveAttribute("aria-selected", "false");
+    expect(current).toHaveAttribute("tabindex", "-1");
+    expect(current).toHaveFocus();
+    expect(
+      screen.getByRole("tabpanel", { name: "열린 질문" }),
+    ).toBeVisible();
+    expect(document.getElementById("focus-panel-current")).toHaveAttribute(
+      "hidden",
+    );
+
+    await router.navigate("/?focus=decision&state=latest-empty#latest");
+
+    await waitFor(() => {
+      expect(screen.getByRole("tab", { name: "최근 결정" })).toHaveAttribute(
+        "aria-selected",
+        "true",
+      );
+    });
+    expect(router.state.location).toMatchObject({
+      pathname: "/",
+      search: "?focus=decision&state=latest-empty",
+      hash: "#latest",
+    });
+    expect(screen.getByRole("tab", { name: "최근 결정" })).toHaveAttribute(
+      "tabindex",
+      "0",
+    );
+    expect(screen.getByRole("tabpanel", { name: "최근 결정" })).toBeVisible();
+    expect(screen.getAllByRole("tabpanel")).toHaveLength(1);
+  });
+
   it("preserves the source home empty and error states", () => {
     const emptyView = renderDiscoveryRoute("TECH_LOG_HOME", "/?state=latest-empty");
     expect(screen.getByText("아직 공개된 기록이 없습니다.")).toHaveClass(
@@ -321,6 +387,86 @@ describe("TechLog explore discovery", () => {
     ).not.toBeInTheDocument();
     expect(container.querySelector(".site-frame")).not.toBeNull();
   });
+
+  it("recovers a rejecting registered not-found runtime under its own chunk contract", async () => {
+    let rejectNotFound: ((reason?: unknown) => void) | undefined;
+    const LazyNotFound = lazy(
+      () =>
+        new Promise<{ default: typeof NotFoundPage }>((_resolve, reject) => {
+          rejectNotFound = reject;
+        }),
+    );
+    const notFoundChunkRead = vi.fn(() => "assets/not-found.js");
+    const exploreKindChunkRead = vi.fn(() => "assets/explore-kind.js");
+    const routeChunks = {
+      get "route-not-found"() {
+        return notFoundChunkRead();
+      },
+      get "route-tech-log-explore-kind"() {
+        return exploreKindChunkRead();
+      },
+    };
+    const release = {
+      buildId: "task-7-test-build",
+      releaseId: "task-7-test-release",
+      configSchemaVersion: "1",
+      apiContractVersion: "1",
+      assetManifestHash: "task-7-test-hash",
+      routeChunks,
+    };
+    const record = vi.fn();
+    const techLog = createTechLogFeatureInstalledInput().input;
+    const application = createTestApplication({
+      diagnostics: { record },
+      releaseInfo: {
+        getCurrent: async () => release,
+        refresh: async () => release,
+      },
+      featureInputs: { "tech-log": techLog },
+    });
+    const { router, container } = renderDiscoveryRoute(
+      "TECH_LOG_EXPLORE_KIND",
+      "/explore/unknown",
+      { NotFoundComponent: LazyNotFound, application },
+    );
+
+    expect(
+      screen.getByText("화면을 준비하고 있습니다.").closest("section"),
+    ).toHaveAttribute("data-surface", "none");
+    await waitFor(() => expect(rejectNotFound).toBeTypeOf("function"));
+    await act(async () => {
+      rejectNotFound?.(
+        new TypeError("Failed to fetch dynamically imported module"),
+      );
+    });
+
+    expect(
+      await screen.findByRole("heading", {
+        name: "화면 자산을 복구하지 못했습니다.",
+      }),
+    ).toBeVisible();
+    expect(notFoundChunkRead).toHaveBeenCalledOnce();
+    expect(exploreKindChunkRead).not.toHaveBeenCalled();
+    expect(router.state.location.pathname).toBe("/explore/unknown");
+    expect(container.querySelector(".site-frame")).not.toBeNull();
+    expect(
+      screen.queryByRole("heading", { name: "화면을 표시하지 못했습니다." }),
+    ).not.toBeInTheDocument();
+
+    const routeChangedRecords = record.mock.calls
+      .map(([entry]) => entry)
+      .filter((entry) => entry.eventId === "route.changed");
+    expect(routeChangedRecords).toEqual([
+      expect.objectContaining({
+        context: expect.objectContaining({
+          route_id: "TECH_LOG_EXPLORE_KIND",
+        }),
+      }),
+    ]);
+    expect(
+      record.mock.calls.some(([entry]) => entry.eventId === "ui.render.failed"),
+    ).toBe(false);
+  });
 });
 
 describe("TechLog search discovery", () => {