feat(web-admin): add list table viewport height formula

Pure calc keeps pagination visible with a 10px bottom gap for main list scroll UX.

Co-authored-by: Cursor <cursoragent@cursor.com>

web-admin/scripts/check-list-table-viewport-height.ts

@@ -0,0 +1,55 @@
+import assert from 'node:assert/strict'
+import {
+  LIST_TABLE_VIEWPORT_BOTTOM_GAP,
+  LIST_TABLE_VIEWPORT_MIN_HEIGHT,
+  calcListTableViewportHeight
+} from '../src/composables/listTableViewportHeight'
+
+assert.equal(LIST_TABLE_VIEWPORT_BOTTOM_GAP, 10)
+assert.equal(LIST_TABLE_VIEWPORT_MIN_HEIGHT, 240)
+
+// contentBottom=1000, tableTop=200, pager=48 → 1000-200-48-10 = 742
+assert.equal(
+  calcListTableViewportHeight({
+    contentViewportBottom: 1000,
+    tableTop: 200,
+    pagerHeight: 48
+  }),
+  742
+)
+
+// 无分页
+assert.equal(
+  calcListTableViewportHeight({
+    contentViewportBottom: 800,
+    tableTop: 100,
+    pagerHeight: 0
+  }),
+  690
+)
+
+// 过矮时夹到 minHeight
+assert.equal(
+  calcListTableViewportHeight({
+    contentViewportBottom: 400,
+    tableTop: 300,
+    pagerHeight: 48,
+    minHeight: 240,
+    bottomGap: 10
+  }),
+  240
+)
+
+// 自定义 min / gap
+assert.equal(
+  calcListTableViewportHeight({
+    contentViewportBottom: 1000,
+    tableTop: 100,
+    pagerHeight: 40,
+    minHeight: 100,
+    bottomGap: 16
+  }),
+  844
+)
+
+console.log('check-list-table-viewport-height: ok')