feat(ui): unify list-page enterprise visual pattern

frontend/src/views/ia/ProjectMilestones.vue

@@ -1,8 +1,8 @@
 <template>
-  <div class="page">
-    <div v-if="study.currentStudy" class="unified-shell">
-      <section class="unified-section">
-        <div class="card-header">
+  <div class="page ctms-page-shell">
+    <div v-if="study.currentStudy" class="unified-shell ctms-table-card">
+      <section class="unified-action-bar">
+        <div class="card-header ctms-page-header-row">
           <div>
             <div class="card-title">{{ TEXT.modules.projectMilestones.listTitle }}</div>
             <div class="card-subtitle">
@@ -21,7 +21,8 @@
             <el-button size="small" @click="loadMilestones">{{ TEXT.common.actions.refresh }}</el-button>
           </div>
         </div>
-
+      </section>
+      <section class="unified-section ctms-page-content-grid">
         <el-table :data="rows" v-loading="loading" class="ctms-table" style="width: 100%">
           <el-table-column prop="name" :label="TEXT.modules.projectMilestones.columns.name" min-width="140" />
           <el-table-column prop="planDate" :label="TEXT.modules.projectMilestones.columns.planDate" min-width="170">

frontend/src/views/ia/RiskIssueMonitoringVisits.vue

@@ -1,7 +1,7 @@
 <template>
-  <div class="page">
+  <div class="page ctms-page-shell">
     <template v-if="study.currentStudy">
-      <el-card shadow="never" class="main-content-card unified-shell">
+      <el-card shadow="never" class="main-content-card unified-shell ctms-table-card">
         <div class="filter-container unified-action-bar">
           <div class="filter-left">
             <el-form :inline="true" :model="filters" class="filter-form">

frontend/src/views/ia/RiskIssuePd.vue

@@ -1,6 +1,6 @@
 <template>
-  <div class="page">
-    <el-card shadow="never" class="main-content-card unified-shell">
+  <div class="page ctms-page-shell">
+    <el-card shadow="never" class="main-content-card unified-shell ctms-table-card">
       <div class="filter-container unified-action-bar">
         <el-form :inline="true" class="filter-form">
           <el-form-item class="filter-item-form">

frontend/src/views/ia/RiskIssueSae.vue

@@ -1,6 +1,6 @@
 <template>
-  <div class="page">
-    <el-card shadow="never" class="main-content-card unified-shell">
+  <div class="page ctms-page-shell">
+    <el-card shadow="never" class="main-content-card unified-shell ctms-table-card">
       <div class="filter-container unified-action-bar">
         <el-form :inline="true" class="filter-form">
           <el-form-item class="filter-item-form">

frontend/src/views/ia/SubjectManagement.vue

@@ -1,6 +1,6 @@
 <template>
-  <div class="page">
-    <el-card shadow="never" class="main-content-card unified-shell">
+  <div class="page ctms-page-shell">
+    <el-card shadow="never" class="main-content-card unified-shell ctms-table-card">
       <div class="filter-container unified-action-bar">
         <el-form :inline="true" :model="filters" class="filter-form">
           <el-form-item label="" class="filter-item-form">