docs(pages): clarify page driver component boundaries

Add inline comments to page components documenting how page models,
v-model state, and emitted user intents flow through the page driver.

This clarifies that page components remain presentation-focused while
routing, dialog state, CRUD side effects, and command handling stay in
the page driver or related composables.docs(pages): clarify page driver component boundaries

Add inline comments to page components documenting how page models,
v-model state, and emitted user intents flow through the page driver.

This clarifies that page components remain presentation-focused while
routing, dialog state, CRUD side effects, and command handling stay in
the page driver or related composables.

src/components/pages/PageMasterDetailBMaintenance.vue

@@ -1,10 +1,12 @@
 <template>
+  <!-- Page component 組合 PageMaint 外殼、主檔表格、子檔區與 dialog；流程狀態集中在本頁 script。 -->
   <page-maint
     :search-panel-open="searchPanelOpen"
     :title="page.title"
     @create="openAddDialog"
     @toggle-search="searchPanelOpen = !searchPanelOpen"
   >
+    <!-- 搜尋欄位放在 PageMaint 的 search-fields slot，讓外殼固定、欄位由頁面決定。 -->
     <template #search-fields>
       <v-col cols="12" md="2">
         <div id="search-student-id-label" class="text-body-2 text-medium-emphasis pl-2">學號</div>
@@ -78,6 +80,7 @@
         <v-btn color="primary" disabled :prepend-icon="mdiMagnify" variant="tonal">查詢</v-btn>
       </v-col>
     </template>
+    <!-- table slot 放主檔表格與列操作，操作事件再交給頁面流程函式處理。 -->
     <template #table>
       <v-data-table
         v-model:page="currentPage"