修改完成

tests/f09-media-upload-contract.ps1

@@ -63,6 +63,15 @@ foreach ($forbidden in @(
   if ($page.Contains($forbidden)) { throw "F09 retains forbidden dependency: $forbidden" }
 }
 
+foreach ($requiredPosition in @(
+  '(?s)\.media-photo-tile\s*\{[^}]*position:\s*relative;',
+  '(?s)\.media-photo-order,\s*\.media-photo-current,\s*\.media-photo-status\s*\{[^}]*position:\s*absolute;',
+  '(?s)\.media-photo-remove\s*\{[^}]*position:\s*absolute;'
+)) {
+  if ($page -notmatch $requiredPosition) { throw "F09 required thumbnail overlay boundary missing: $requiredPosition" }
+}
+if ([regex]::Matches($page, 'position\s*:').Count -ne 3) { throw 'F09 must keep only thumbnail badges and their local photo boundary positioned' }
+
 if ($catalog -match '(?m)^\s*f09\s*:') {
   throw 'F09 obsolete page-catalog owner must be removed'
 }