diff --git a/frontend-web/src/components/workspace/appearance-controls.tsx b/frontend-web/src/components/workspace/appearance-controls.tsx
index a8ff1097..77864f64 100644
--- a/frontend-web/src/components/workspace/appearance-controls.tsx
+++ b/frontend-web/src/components/workspace/appearance-controls.tsx
@@ -223,22 +223,19 @@ const LAYOUT_OPTIONS = [
  * 界面模式（全量 / 简洁）下拉切换。换肤旁并排，图标 + 下拉：
  *   - 简洁模式 ChatPage 顶栏（全局顶栏被隐藏）。
  *   - 全量模式 Header 右上角。
- * 用户未显式设置过界面模式时（mode === undefined），当前态按调用方所在的实际界面
- * 兜底——`fallback` 指明这一回退值（Header 传 "full"，ChatPage 传 "compact"）。
+ * 当前态为有效界面模式（用户自选 > 管理员系统默认 > 内置简洁默认）——
+ * useLayoutMode 总会返回具体值，不再有 undefined 兜底。
  */
 export function LayoutModeSwitcher({
   tone,
-  fallback = "compact",
   navigateTo = "/page/workspace/chats/new",
 }: {
   tone: AppearanceControlTone;
-  fallback?: "full" | "compact";
   navigateTo?: string | null;
 }) {
   const [mode, setLayoutMode] = useLayoutMode();
   const navigate = useNavigate();
-  const current = mode ?? fallback;
-  const TriggerIcon = current === "full" ? PanelLeftIcon : LayoutIcon;
+  const TriggerIcon = mode === "full" ? PanelLeftIcon : LayoutIcon;
 
   if (env.FORCE_COLLAPSED_SIDEBAR || isHideChromeActive()) return null;
 
@@ -262,7 +259,7 @@ export function LayoutModeSwitcher({
         <DropdownMenuSeparator />
         {LAYOUT_OPTIONS.map((option) => {
           const Icon = option.icon;
-          const active = current === option.id;
+          const active = mode === option.id;
           return (
             <DropdownMenuItem
               key={option.id}
diff --git a/frontend-web/src/components/workspace/settings/appearance-settings-page.tsx b/frontend-web/src/components/workspace/settings/appearance-settings-page.tsx
index 804a4772..d65b524f 100644
--- a/frontend-web/src/components/workspace/settings/appearance-settings-page.tsx
+++ b/frontend-web/src/components/workspace/settings/appearance-settings-page.tsx
@@ -188,7 +188,7 @@ export function AppearanceSettingsPage({ onClose }: { onClose?: () => void }) {
   const globalDefault = appearance?.default_theme ?? "light";
   const globalSkillView = appearance?.default_skill_view ?? "list";
   const globalAgentView = appearance?.default_agent_view ?? "card";
-  const globalLayoutMode = appearance?.default_layout_mode ?? "full";
+  const globalLayoutMode = appearance?.default_layout_mode ?? "compact";
   const globalDefaultLabel = useMemo(() => {
     const customTheme = (appearance?.custom_themes ?? []).find(
       (preset) => preset.id === globalDefault,
@@ -201,7 +201,7 @@ export function AppearanceSettingsPage({ onClose }: { onClose?: () => void }) {
     if (globalDefault === "lightyellow") return "浅黄色";
     return "浅蓝";
   }, [appearance?.custom_themes, globalDefault]);
-  // 有效界面模式：用户自己选过则以其为准，否则跟随管理员系统默认（再否则会话级回退）。
+  // 有效界面模式：用户自己选过则以其为准，否则跟随管理员系统默认（再否则内置默认简洁模式）。
   const [effectiveLayoutMode, setLayoutMode] = useLayoutMode();
   const cleanupWords =
     citationDisplay?.cleanup_words ?? settings.display.citationCleanupWords ?? [];
diff --git a/frontend-web/src/core/system-settings/hooks.ts b/frontend-web/src/core/system-settings/hooks.ts
index 5ec98457..8e51b828 100644
--- a/frontend-web/src/core/system-settings/hooks.ts
+++ b/frontend-web/src/core/system-settings/hooks.ts
@@ -164,19 +164,15 @@ export function useViewMode(
 /**
  * Effective interface layout mode (full chrome vs compact). A user's own choice
  * (persisted in local settings) wins; otherwise the admin-configured system
- * default applies; otherwise `undefined` (callers fall back to the session-level
- * `sidebarEnabled` flag set by portal / yUserId login). `setMode` persists the
- * user's override locally.
+ * default applies; otherwise the built-in default is compact (简洁模式).
+ * `setMode` persists the user's override locally.
  */
-export function useLayoutMode(): [
-  LayoutMode | undefined,
-  (mode: LayoutMode) => void,
-] {
+export function useLayoutMode(): [LayoutMode, (mode: LayoutMode) => void] {
   const [settings, setSettings] = useLocalSettings();
   const { data: appearance } = useAppearanceSettings();
   const userOverride = settings.display.layoutMode;
   const adminDefault = appearance?.default_layout_mode;
-  const mode = userOverride ?? adminDefault;
+  const mode: LayoutMode = userOverride ?? adminDefault ?? "compact";
   const setMode = (next: LayoutMode) =>
     setSettings("display", { layoutMode: next });
   return [mode, setMode];
diff --git a/frontend-web/src/pages/ChatPage.tsx b/frontend-web/src/pages/ChatPage.tsx
index 6e17b22d..39a5ef93 100644
--- a/frontend-web/src/pages/ChatPage.tsx
+++ b/frontend-web/src/pages/ChatPage.tsx
@@ -37,7 +37,6 @@ import { UserIdentityBadge } from "@/components/workspace/user-identity-badge";
 import { CompactModeGuide } from "@/components/workspace/compact-mode-guide";
 import { Welcome } from "@/components/workspace/welcome";
 import { CompactWelcome } from "@/components/workspace/compact-welcome";
-import { readSidebarEnabled } from "@/core/page-layout/sidebar-enabled";
 import {
   buildFullChatNavigationPath,
   isChatsIframeWorkspacePath,
@@ -129,7 +128,7 @@ export default function ChatPage() {
   const { open: historySidebarOpen, toggleSidebar: toggleHistorySidebar } =
     useSidebar();
   const { t } = useI18n();
-  // 有效界面模式：用户自选 > 管理员系统默认 > （下方再回退会话级 sidebarEnabled）
+  // 有效界面模式：用户自选 > 管理员系统默认 > 内置默认「简洁模式」
   const [effectiveLayoutMode] = useLayoutMode();
   const [showFollowups, setShowFollowups] = useState(false);
   const [hasStartedConversation, setHasStartedConversation] = useState(false);
@@ -662,16 +661,10 @@ export default function ChatPage() {
   const isLandingState = isNewThread && !hasStartedConversation;
   // 紧凑模式（正常 App，有外层页面侧栏）落地态：用 CM 参考图样式重画；
   // 判定与 PageRoutes 的 compactWorkspaceSidebar(pageSidebarAllowed) 保持一致 ——
-  // 优先看外观设置的「全量/简洁」，未设置过才回退到会话级 sidebarEnabled。否则用户显式
-  // 选「全量」时 PageRoutes 已挂出顶栏+侧栏，这里却还按旧 sidebarEnabled 判定，导致深蓝
-  // 主题底图(workspace-chat-bg)不生效。非紧凑（嵌入/standalone）保持原样。
-  const layoutMode = effectiveLayoutMode;
+  // 用 useLayoutMode 的有效界面模式（用户自选 > 管理员系统默认 > 内置简洁默认），
+  // 与 PageRoutes 的 chrome 判定同源。非紧凑（嵌入/standalone）保持原样。
   const chromeByPreference =
-    fullChatMode || layoutMode === "full"
-      ? true
-      : layoutMode === "compact"
-        ? false
-        : readSidebarEnabled();
+    fullChatMode || effectiveLayoutMode === "full" ? true : false;
   const compactChrome =
     chromeByPreference && !isChatsIframeWorkspacePath(pathname);
   const compactLanding = isLandingState && compactChrome;
diff --git a/frontend-web/src/pages/PageRoutes.tsx b/frontend-web/src/pages/PageRoutes.tsx
index 50bb0dc4..e29fa11c 100644
--- a/frontend-web/src/pages/PageRoutes.tsx
+++ b/frontend-web/src/pages/PageRoutes.tsx
@@ -5,7 +5,6 @@ import { PageSidebar } from "@/components/page-sidebar";
 import { PageSidebarDark } from "@/components/page-sidebar-dark";
 import { CompactToolbox } from "@/components/workspace/compact-toolbox";
 import { isChatsIframeWorkspacePath } from "@/core/page-layout/chats-iframe-route";
-import { readSidebarEnabled } from "@/core/page-layout/sidebar-enabled";
 import { isWujieEnv } from "@/core/embed/wujie";
 import {
   isEmbedActive,
@@ -34,7 +33,6 @@ import { RoundtableJobNotifier } from "@/roundtable-planning/components/Roundtab
 function PageLayout() {
   const [collapsed, setCollapsed] = useState(false);
   const forceCollapsedSidebar = env.FORCE_COLLAPSED_SIDEBAR;
-  const sidebarEnabled = useMemo(() => readSidebarEnabled(), []);
   const location = useLocation();
   const { theme } = useTheme();
   const isDark = theme === "dark";
@@ -45,17 +43,11 @@ function PageLayout() {
   const thirdLevel = useActiveThirdLevel();
   const lightExpanded = lightNarrowSidebar && thirdLevel.length > 0;
   // 界面模式（外观设置）：用户显式选「全量/简洁」时以其为准；否则跟随管理员系统默认
-  // (default_layout_mode)；两者都没有才回退到会话级 sidebarEnabled（外部门户/yUserId
-  // 登录时置位）这一旧默认。这样无论是否走门户登录，「全量↔简洁」都能真正控制顶栏+侧边栏。
+  // (default_layout_mode)；两者都没有时使用内置默认「简洁模式」（useLayoutMode 兜底，
+  // 不再回退到会话级 sidebarEnabled 旧默认）。「全量↔简洁」始终能真正控制顶栏+侧边栏。
   const [layoutMode] = useLayoutMode();
   const chromeByPreference =
-    forceCollapsedSidebar
-      ? false
-      : layoutMode === "full"
-        ? true
-        : layoutMode === "compact"
-          ? false
-          : sidebarEnabled;
+    forceCollapsedSidebar ? false : layoutMode === "compact" ? false : true;
   // iframe 嵌入模式（外部系统 `&embed=1`，按标签页 sessionStorage）：去掉全局导航栏 + 侧边栏，
   // 只留问答/会商工作区本体。按 location 重算以跟随页内导航；非嵌入标签页恒为 false，不受影响。
   const embedActive = useMemo(
diff --git a/frontend-web/src/strategy-components/Header.tsx b/frontend-web/src/strategy-components/Header.tsx
index a1dbde5c..baf95239 100644
--- a/frontend-web/src/strategy-components/Header.tsx
+++ b/frontend-web/src/strategy-components/Header.tsx
@@ -170,10 +170,7 @@ const Header = ({ collapsed }: HeaderProps) => {
       <CompactShortcutButtons tone={headerTone} />
       <ThemeSwitcher tone={headerTone} />
 
-      <LayoutModeSwitcher
-        tone={headerTone}
-        fallback="full"
-      />
+      <LayoutModeSwitcher tone={headerTone} />
 
       <Button
         type="button"
diff --git a/offline-backend-20260512/backend/app/report_collaboration/contracts/ids.py b/offline-backend-20260512/backend/app/report_collaboration/contracts/ids.py
index 8fbf5a6f..df2c8e42 100644
--- a/offline-backend-20260512/backend/app/report_collaboration/contracts/ids.py
+++ b/offline-backend-20260512/backend/app/report_collaboration/contracts/ids.py
@@ -4,23 +4,35 @@ from __future__ import annotations
 
 import re
 
-_NODE_RUN_ID_RE = re.compile(r"^(?P<node_id>.+)-attempt(?P<attempt>\d+)$")
+_NODE_RUN_ID_RE = re.compile(r"^(?P<scope>.+)-attempt(?P<attempt>\d+)$")
 
 
-def make_node_run_id(node_id: str, attempt: int) -> str:
-    """Return ``${node_id}-attempt{attempt}``. Random UUIDs are forbidden."""
+def make_node_run_id(run_id: str, node_id: str, attempt: int) -> str:
+    """Return ``${run_id}-${node_id}-attempt{attempt}``. Random UUIDs are forbidden.
 
+    The run dimension is part of the id because the node-runs table primary
+    key is ``node_run_id`` alone: without it, two runs reusing the same plan
+    template would collide on ``${node_id}-attempt{n}``.
+    """
+
+    if not run_id or run_id.strip() != run_id:
+        raise ValueError("run_id must be a non-empty trimmed string")
     if not node_id or node_id.strip() != node_id:
         raise ValueError("node_id must be a non-empty trimmed string")
     if attempt < 1:
         raise ValueError("attempt must be >= 1")
-    return f"{node_id}-attempt{attempt}"
+    return f"{run_id}-{node_id}-attempt{attempt}"
 
 
 def parse_node_run_id(node_run_id: str) -> tuple[str, int]:
-    """Split a canonical node_run_id back into ``(node_id, attempt)``."""
+    """Split a canonical node_run_id tail back into ``(..., attempt)``.
+
+    The returned first element is the run-scoped node portion
+    (``${run_id}-${node_id}``); callers that need the bare node id should
+    strip the known run prefix themselves.
+    """
 
     match = _NODE_RUN_ID_RE.match(node_run_id or "")
     if match is None:
         raise ValueError(f"invalid node_run_id: {node_run_id!r}")
-    return match.group("node_id"), int(match.group("attempt"))
+    return match.group("scope"), int(match.group("attempt"))
diff --git a/offline-backend-20260512/backend/app/report_collaboration/execution/ledger.py b/offline-backend-20260512/backend/app/report_collaboration/execution/ledger.py
index 79ab4c8d..fba3d216 100644
--- a/offline-backend-20260512/backend/app/report_collaboration/execution/ledger.py
+++ b/offline-backend-20260512/backend/app/report_collaboration/execution/ledger.py
@@ -365,7 +365,7 @@ class TaskLedger:
             )
             attempt = int(node.get("attempt") or 0) + 1
             replacement = {
-                "node_run_id": make_node_run_id(node_id, attempt),
+                "node_run_id": make_node_run_id(run_id, node_id, attempt),
                 "session_id": run["session_id"],
                 "run_id": run_id,
                 "node_id": node_id,
@@ -449,7 +449,7 @@ class TaskLedger:
         nxt = assignment.attempt + 1
         await self._store.save_node_run(
             {
-                "node_run_id": make_node_run_id(assignment.node_id, nxt),
+                "node_run_id": make_node_run_id(assignment.run_id, assignment.node_id, nxt),
                 "session_id": assignment.session_id,
                 "run_id": assignment.run_id,
                 "node_id": assignment.node_id,
@@ -518,7 +518,7 @@ class TaskLedger:
         nxt = attempt + 1
         await self._store.save_node_run(
             {
-                "node_run_id": make_node_run_id(node_id, nxt),
+                "node_run_id": make_node_run_id(str(run["id"]), node_id, nxt),
                 "session_id": run["session_id"],
                 "run_id": run["id"],
                 "node_id": node_id,
@@ -540,7 +540,7 @@ class TaskLedger:
             session_id=str(run["session_id"]),
             run_id=str(run["id"]),
             event_type="node.attempt.created",
-            data={"node_id": node_id, "node_run_id": make_node_run_id(node_id, nxt), "attempt": nxt, "reason": "targeted_rework"},
+            data={"node_id": node_id, "node_run_id": make_node_run_id(str(run["id"]), node_id, nxt), "attempt": nxt, "reason": "targeted_rework"},
         )
         return True
 
diff --git a/offline-backend-20260512/backend/app/report_collaboration/execution/recovery.py b/offline-backend-20260512/backend/app/report_collaboration/execution/recovery.py
index e8b21e59..ed5dc996 100644
--- a/offline-backend-20260512/backend/app/report_collaboration/execution/recovery.py
+++ b/offline-backend-20260512/backend/app/report_collaboration/execution/recovery.py
@@ -127,7 +127,7 @@ async def _maybe_open_next_attempt(
     if attempt >= _max_attempts(node, spec):
         return
     nxt = attempt + 1
-    node_run_id = make_node_run_id(str(node["node_id"]), nxt)
+    node_run_id = make_node_run_id(str(run["id"]), str(node["node_id"]), nxt)
     await store.save_node_run(
         {
             "node_run_id": node_run_id,
diff --git a/offline-backend-20260512/backend/packages/harness/deerflow/config/system_settings.py b/offline-backend-20260512/backend/packages/harness/deerflow/config/system_settings.py
index cbfa0257..2c2af926 100644
--- a/offline-backend-20260512/backend/packages/harness/deerflow/config/system_settings.py
+++ b/offline-backend-20260512/backend/packages/harness/deerflow/config/system_settings.py
@@ -236,8 +236,8 @@ class AppearanceSettings(BaseModel):
         description="Default agent list display mode for users who haven't picked their own (card / list)",
     )
     default_layout_mode: Literal["full", "compact"] = Field(
-        default="full",
-        description="Default interface layout for users who haven't picked their own — full (sidebar + header) / compact (hidden)",
+        default="compact",
+        description="Default interface layout for users who haven't picked their own — compact (hidden) / full (sidebar + header)",
     )
     compact_shortcut_buttons: list[CompactShortcutButton] = Field(
         default_factory=_default_compact_shortcut_buttons,
diff --git a/offline-backend-20260512/backend/packages/harness/deerflow/persistence/report_collaboration/codec.py b/offline-backend-20260512/backend/packages/harness/deerflow/persistence/report_collaboration/codec.py
index 4eb1a40c..c10065ef 100644
--- a/offline-backend-20260512/backend/packages/harness/deerflow/persistence/report_collaboration/codec.py
+++ b/offline-backend-20260512/backend/packages/harness/deerflow/persistence/report_collaboration/codec.py
@@ -55,8 +55,14 @@ def loads_dict(value: Any) -> dict[str, Any]:
     return {}
 
 
-def make_node_run_id(node_id: str, attempt: int) -> str:
-    return f"{node_id}-attempt{attempt}"
+def make_node_run_id(run_id: str, node_id: str, attempt: int) -> str:
+    """Return ``${run_id}-${node_id}-attempt{attempt}``.
+
+    The node-runs table primary key is ``node_run_id`` alone, so the id must
+    carry the run dimension: two runs sharing a plan template would otherwise
+    collide on the same deterministic ``${node_id}-attempt{n}`` string.
+    """
+    return f"{run_id}-{node_id}-attempt{attempt}"
 
 
 def is_terminal_run(status: str) -> bool:
diff --git a/offline-backend-20260512/backend/packages/harness/deerflow/persistence/report_collaboration/memory.py b/offline-backend-20260512/backend/packages/harness/deerflow/persistence/report_collaboration/memory.py
index 5c2aae0c..c4a537b0 100644
--- a/offline-backend-20260512/backend/packages/harness/deerflow/persistence/report_collaboration/memory.py
+++ b/offline-backend-20260512/backend/packages/harness/deerflow/persistence/report_collaboration/memory.py
@@ -494,7 +494,7 @@ class MemoryReportCollaborationStore(ReportCollaborationStore):
             node_id = str(node.get("id") or "")
             if not node_id:
                 continue
-            node_run_id = make_node_run_id(node_id, 1)
+            node_run_id = make_node_run_id(run_id, node_id, 1)
             role_key = str(node.get("role_key") or "")
             self._node_runs[node_run_id] = {
                 "node_run_id": node_run_id,
diff --git a/offline-backend-20260512/backend/packages/harness/deerflow/persistence/report_collaboration/sql.py b/offline-backend-20260512/backend/packages/harness/deerflow/persistence/report_collaboration/sql.py
index 96b159ae..827beea4 100644
--- a/offline-backend-20260512/backend/packages/harness/deerflow/persistence/report_collaboration/sql.py
+++ b/offline-backend-20260512/backend/packages/harness/deerflow/persistence/report_collaboration/sql.py
@@ -884,7 +884,7 @@ class SqlReportCollaborationStore(ReportCollaborationStore):
                 snapshot = (role_snapshots or {}).get(role_key)
                 db.add(
                     ReportCollaborationNodeRunRow(
-                        node_run_id=make_node_run_id(node_id, 1),
+                        node_run_id=make_node_run_id(run_id, node_id, 1),
                         session_id=session_id,
                         run_id=run_id,
                         node_id=node_id,
diff --git a/offline-backend-20260512/backend/tests/test_report_collaboration_contracts.py b/offline-backend-20260512/backend/tests/test_report_collaboration_contracts.py
index 9fa150e1..409be05c 100644
--- a/offline-backend-20260512/backend/tests/test_report_collaboration_contracts.py
+++ b/offline-backend-20260512/backend/tests/test_report_collaboration_contracts.py
@@ -101,10 +101,12 @@ def test_event_envelope_accepts_snake_or_camel_aliases() -> None:
 
 
 def test_node_run_id_is_deterministic() -> None:
-    assert make_node_run_id("research_brand", 2) == "research_brand-attempt2"
-    assert parse_node_run_id("research_brand-attempt2") == ("research_brand", 2)
+    assert make_node_run_id("rcr_x", "research_brand", 2) == "rcr_x-research_brand-attempt2"
+    assert parse_node_run_id("rcr_x-research_brand-attempt2") == ("rcr_x-research_brand", 2)
     with pytest.raises(ValueError):
-        make_node_run_id("research_brand", 0)
+        make_node_run_id("rcr_x", "research_brand", 0)
+    with pytest.raises(ValueError):
+        make_node_run_id("", "research_brand", 1)
     with pytest.raises(ValueError):
         parse_node_run_id("random-uuid")
 
diff --git a/offline-backend-20260512/backend/tests/test_report_collaboration_dispatcher.py b/offline-backend-20260512/backend/tests/test_report_collaboration_dispatcher.py
index 9b6e3edd..dbfd8d83 100644
--- a/offline-backend-20260512/backend/tests/test_report_collaboration_dispatcher.py
+++ b/offline-backend-20260512/backend/tests/test_report_collaboration_dispatcher.py
@@ -175,7 +175,7 @@ async def test_recovery_preserves_completed_nodes() -> None:
     write["status"] = "running"
     await store.save_node_run(write)
     report = await recover_orphaned_attempts(store, run_id)
-    assert "research-attempt1" in report.preserved_completed
+    assert f"{run_id}-research-attempt1" in report.preserved_completed
     assert write["node_run_id"] in report.interrupted_node_run_ids
     latest = {item["node_id"]: item for item in await store.list_node_runs(run_id)}
     assert latest["research"]["status"] == "completed"
diff --git a/offline-backend-20260512/backend/tests/test_report_collaboration_node_machine.py b/offline-backend-20260512/backend/tests/test_report_collaboration_node_machine.py
index 50b3bb7a..69e96685 100644
--- a/offline-backend-20260512/backend/tests/test_report_collaboration_node_machine.py
+++ b/offline-backend-20260512/backend/tests/test_report_collaboration_node_machine.py
@@ -71,11 +71,12 @@ def test_completed_reopen_creates_new_attempt_id() -> None:
     assert can_transition_node("reopened", "queued")
     with pytest.raises(IllegalNodeTransition):
         require_transition("completed", "queued")
-    first = make_node_run_id("writer", 1)
-    second = make_node_run_id("writer", 2)
-    assert first == "writer-attempt1"
-    assert second == "writer-attempt2"
+    first = make_node_run_id("rcr_x", "writer", 1)
+    second = make_node_run_id("rcr_x", "writer", 2)
+    assert first == "rcr_x-writer-attempt1"
+    assert second == "rcr_x-writer-attempt2"
     assert first != second
+    assert make_node_run_id("rcr_y", "writer", 1) != first
 
 
 def test_planned_is_bootstrap_source() -> None:
diff --git a/offline-backend-20260512/backend/tests/test_report_collaboration_runner.py b/offline-backend-20260512/backend/tests/test_report_collaboration_runner.py
index b669148a..6b1cf3cc 100644
--- a/offline-backend-20260512/backend/tests/test_report_collaboration_runner.py
+++ b/offline-backend-20260512/backend/tests/test_report_collaboration_runner.py
@@ -152,7 +152,7 @@ async def test_waves_researcher_before_writer_and_text_does_not_complete() -> No
     assert advice[0]["data"]["suggested_next_node_ids"] == ["write"]
     agents = await store.list_agent_runs(run_id)
     phases = {item["node_run_id"]: item["phase_id"] for item in agents}
-    assert phases["research-attempt1"] != phases["write-attempt1"]
+    assert phases[f"{run_id}-research-attempt1"] != phases[f"{run_id}-write-attempt1"]
 
 
 @pytest.mark.asyncio