diff --git a/mateclaw-ui/src/i18n/locales/en-US.ts b/mateclaw-ui/src/i18n/locales/en-US.ts
index 6c09c4ad..fd70811d 100644
--- a/mateclaw-ui/src/i18n/locales/en-US.ts
+++ b/mateclaw-ui/src/i18n/locales/en-US.ts
@@ -1340,6 +1340,10 @@ export default {
     loadMore: 'Load {n} more',
     filteredByRaw: 'Filtered by source material',
     clearFilter: 'Clear filter',
+    systemPageBadge: 'System',
+    systemPageHint: 'overview / log are built-in system pages — they can\'t be deleted',
+    lockedPageBadge: 'Locked',
+    lockedPageHint: 'This page is locked — AI tools and batch operations skip it',
     pageTypes: {
       concept: 'Concepts',
       person: 'People',
diff --git a/mateclaw-ui/src/i18n/locales/zh-CN.ts b/mateclaw-ui/src/i18n/locales/zh-CN.ts
index c469b57f..b140207a 100644
--- a/mateclaw-ui/src/i18n/locales/zh-CN.ts
+++ b/mateclaw-ui/src/i18n/locales/zh-CN.ts
@@ -1350,6 +1350,10 @@ export default {
     loadMore: '加载更多 {n} 条',
     filteredByRaw: '按原始材料过滤',
     clearFilter: '清除过滤',
+    systemPageBadge: '系统页',
+    systemPageHint: 'overview / log 是知识库自带的系统页，无法删除',
+    lockedPageBadge: '已锁定',
+    lockedPageHint: '该页被手动锁定，AI 工具与批量操作不会修改或删除',
     pageTypes: {
       concept: '概念',
       person: '人物',
diff --git a/mateclaw-ui/src/stores/useWikiStore.ts b/mateclaw-ui/src/stores/useWikiStore.ts
index 32b07716..86ba8e6d 100644
--- a/mateclaw-ui/src/stores/useWikiStore.ts
+++ b/mateclaw-ui/src/stores/useWikiStore.ts
@@ -46,10 +46,22 @@ export interface WikiPage {
   version: number
   lastUpdatedBy: string
   pageType?: string | null
+  // RFC-051 PR-2: locked=1 blocks AI/tool/UI deletion (combined with pageType=system
+  // for the built-in overview/log pages, but users can lock any page).
+  locked?: number | null
+  // RFC-051 PR-7: archived=1 hides the page from default list/search/related.
+  archived?: number | null
   createTime: string
   updateTime: string
 }
 
+/** RFC-051 PR-8: shared protection check used by viewer + list to gate delete UI. */
+export function isProtectedPage(page: WikiPage | null | undefined): boolean {
+  if (!page) return false
+  if (page.pageType === 'system') return true
+  return page.locked === 1
+}
+
 export const useWikiStore = defineStore('wiki', () => {
   const knowledgeBases = ref<WikiKB[]>([])
   const currentKB = ref<WikiKB | null>(null)
diff --git a/mateclaw-ui/src/views/Wiki/components/WikiPageViewer.vue b/mateclaw-ui/src/views/Wiki/components/WikiPageViewer.vue
index be007ee2..90e488b9 100644
--- a/mateclaw-ui/src/views/Wiki/components/WikiPageViewer.vue
+++ b/mateclaw-ui/src/views/Wiki/components/WikiPageViewer.vue
@@ -29,9 +29,20 @@
         <el-icon><SetUp /></el-icon>
         {{ t('wiki.page.repair') }}
       </button>
-      <button v-if="!editing" class="btn-secondary btn-sm btn-delete" @click="handleDelete">
+      <!-- RFC-051 PR-8: hide delete on protected pages (system / locked). -->
+      <button
+        v-if="!editing && !isProtected"
+        class="btn-secondary btn-sm btn-delete"
+        @click="handleDelete"
+      >
         {{ t('common.delete') }}
       </button>
+      <span v-if="!editing && isSystem" class="system-badge" :title="t('wiki.systemPageHint')">
+        {{ t('wiki.systemPageBadge') }}
+      </span>
+      <span v-if="!editing && isLockedNotSystem" class="locked-badge" :title="t('wiki.lockedPageHint')">
+        {{ t('wiki.lockedPageBadge') }}
+      </span>
     </div>
 
     <!-- Content -->
@@ -79,7 +90,7 @@
 <script setup lang="ts">
 import { ref, computed, watch, onMounted } from 'vue'
 import { useI18n } from 'vue-i18n'
-import { useWikiStore, type WikiPage } from '@/stores/useWikiStore'
+import { useWikiStore, isProtectedPage, type WikiPage } from '@/stores/useWikiStore'
 import { wikiApi } from '@/api/index'
 import { useMarkdownRenderer } from '@/composables/useMarkdownRenderer'
 import { Link, SetUp } from '@element-plus/icons-vue'
@@ -97,6 +108,11 @@ const backlinks = ref<WikiPage[]>([])
 const citationDrawerOpen = ref(false)
 const enrichToast = ref('')
 
+// RFC-051 PR-8: protection state for delete-button gating + badge rendering.
+const isSystem = computed(() => store.currentPage?.pageType === 'system')
+const isProtected = computed(() => isProtectedPage(store.currentPage))
+const isLockedNotSystem = computed(() => isProtected.value && !isSystem.value)
+
 const renderedContent = computed(() => {
   if (!store.currentPage?.content) return ''
   // Build a lookup map: title (normalized) → slug, for resolving [[Title]] links
@@ -208,7 +224,30 @@ onMounted(() => {
 .btn-secondary.btn-delete:hover { background: var(--el-color-danger-light-9, #fef0f0); border-color: var(--el-color-danger-light-5, #fab6b6); }
 .btn-secondary.btn-action { color: var(--mc-primary); }
 
-.page-actions-bar { display: flex; gap: 8px; flex-wrap: wrap; }
+.page-actions-bar { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; }
+
+/* RFC-051 PR-8: protection badges shown next to action buttons. */
+.system-badge,
+.locked-badge {
+  display: inline-flex;
+  align-items: center;
+  padding: 2px 9px;
+  border-radius: 99px;
+  font-size: 11px;
+  font-weight: 600;
+  letter-spacing: 0.02em;
+  user-select: none;
+}
+.system-badge {
+  background: var(--mc-primary-bg);
+  color: var(--mc-primary);
+  border: 1px solid var(--mc-primary);
+}
+.locked-badge {
+  background: var(--mc-bg-elevated);
+  color: var(--mc-text-secondary);
+  border: 1px solid var(--mc-border-light);
+}
 
 /* Summary */
 .page-summary { padding: 16px 20px; background: var(--mc-bg-muted); border-radius: 12px; border-left: 3px solid var(--mc-primary); }
diff --git a/mateclaw-ui/src/views/Wiki/index.vue b/mateclaw-ui/src/views/Wiki/index.vue
index 0ac6f604..73f3030f 100644
--- a/mateclaw-ui/src/views/Wiki/index.vue
+++ b/mateclaw-ui/src/views/Wiki/index.vue
@@ -121,20 +121,29 @@
                   <div v-if="!collapsedGroups.has(group.type)" class="group-items">
                     <div
                       v-for="page in paginatedGroupPages(group)" :key="page.slug"
-                      class="page-item" :class="{ active: !batchMode && store.currentPage?.slug === page.slug }"
+                      class="page-item"
+                      :class="{
+                        active: !batchMode && store.currentPage?.slug === page.slug,
+                        'page-item--system': page.pageType === 'system'
+                      }"
                       @click="batchMode ? toggleSelect(page.slug) : openPage(page.slug)"
                     >
+                      <!-- RFC-051 PR-8: batch checkbox is disabled for protected pages so a stray
+                           batch-delete can't drag in overview/log or any locked page. -->
                       <input
                         v-if="batchMode"
                         type="checkbox"
                         :checked="selectedSlugs.includes(page.slug)"
+                        :disabled="isProtectedPage(page)"
                         class="page-checkbox"
-                        @click.stop="toggleSelect(page.slug)"
+                        @click.stop="!isProtectedPage(page) && toggleSelect(page.slug)"
                       />
                       <div class="page-item-body">
                         <div class="page-item-title">{{ page.title }}</div>
                         <div class="page-item-meta">
                           <span v-if="page.lastUpdatedBy === 'manual'" class="edit-dot manual" title="Manual edit"></span>
+                          <span v-if="page.pageType === 'system'" class="page-flag page-flag--system">{{ t('wiki.systemPageBadge') }}</span>
+                          <span v-else-if="page.locked === 1" class="page-flag page-flag--locked">{{ t('wiki.lockedPageBadge') }}</span>
                           <span class="meta-text">v{{ page.version }}</span>
                         </div>
                       </div>
@@ -156,20 +165,27 @@
               <div class="page-list" v-else>
                 <div
                   v-for="page in paginatedSearch" :key="page.slug"
-                  class="page-item" :class="{ active: !batchMode && store.currentPage?.slug === page.slug }"
+                  class="page-item"
+                  :class="{
+                    active: !batchMode && store.currentPage?.slug === page.slug,
+                    'page-item--system': page.pageType === 'system'
+                  }"
                   @click="batchMode ? toggleSelect(page.slug) : openPage(page.slug)"
                 >
                   <input
                     v-if="batchMode"
                     type="checkbox"
                     :checked="selectedSlugs.includes(page.slug)"
+                    :disabled="isProtectedPage(page)"
                     class="page-checkbox"
-                    @click.stop="toggleSelect(page.slug)"
+                    @click.stop="!isProtectedPage(page) && toggleSelect(page.slug)"
                   />
                   <div class="page-item-body">
                     <div class="page-item-title">{{ page.title }}</div>
                     <div class="page-item-meta">
                       <span class="type-chip">{{ formatGroupLabel(page.pageType || 'other') }}</span>
+                      <span v-if="page.pageType === 'system'" class="page-flag page-flag--system">{{ t('wiki.systemPageBadge') }}</span>
+                      <span v-else-if="page.locked === 1" class="page-flag page-flag--locked">{{ t('wiki.lockedPageBadge') }}</span>
                       <span class="meta-text">v{{ page.version }}</span>
                     </div>
                   </div>
@@ -255,7 +271,7 @@
 <script setup lang="ts">
 import { ref, reactive, computed, onMounted, watch, nextTick } from 'vue'
 import { useI18n } from 'vue-i18n'
-import { useWikiStore } from '@/stores/useWikiStore'
+import { useWikiStore, isProtectedPage } from '@/stores/useWikiStore'
 import { wikiApi } from '@/api/index'
 import RawMaterialPanel from './components/RawMaterialPanel.vue'
 import WikiPageViewer from './components/WikiPageViewer.vue'
@@ -631,6 +647,15 @@ onMounted(() => {
 .edit-dot { width: 5px; height: 5px; border-radius: 9999px; flex-shrink: 0; }
 .edit-dot.manual { background: var(--mc-primary); }
 .page-checkbox { flex-shrink: 0; cursor: pointer; }
+.page-checkbox:disabled { cursor: not-allowed; opacity: 0.4; }
+
+/* RFC-051 PR-8: protection flag chips inside the page-item meta line. */
+.page-flag { font-size: 10px; padding: 1px 6px; border-radius: 99px; font-weight: 600; }
+.page-flag--system { background: var(--mc-primary-bg); color: var(--mc-primary); border: 1px solid var(--mc-primary); }
+.page-flag--locked { background: var(--mc-bg-elevated); color: var(--mc-text-secondary); border: 1px solid var(--mc-border-light); }
+
+/* Subtle accent on the row itself so system pages read as "managed by the system". */
+.page-item--system { border-left: 2px solid var(--mc-primary); padding-left: 6px; }
 
 .load-more-btn {
   width: 100%;