fix(files_versions): create version entity instead of failing when missing

[solracsf]

Summary

A COPY assigns the target a new file id without a version entity, so post_write_hook's updateVersionEntity() raised DoesNotExistException and crashed the request. Handle it in the listener (the caller) by creating the entity for the current content, leaving the backend free to keep throwing.

Error stack

{
  "reqId": "iNwhE8uZnaFbKbyG6WFq",
  "level": 3,
  "time": "2025-09-11T09:48:09+02:00",
  "remoteAddr": "91.6.26.13",
  "user": "fzez",
  "app": "no app in context",
  "method": "COPY",
  "url": "/remote.php/dav/files/user/folder/file.md",
  "message": "Exception thrown: OCP\\AppFramework\\Db\\DoesNotExistException",
  "userAgent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/137.0.0.0 Safari/537.36",
  "version": "30.0.14.1",
  "exception": {
    "Exception": "OCP\\AppFramework\\Db\\DoesNotExistException",
    "Message": "Did expect one result but found none when executing: query \"SELECT * FROM `*PREFIX*files_versions` WHERE (`file_id` = :dcValue1) AND (`timestamp` = :dcValue2)\"; ",
    "Code": 0,
    "Trace": [
      {
        "file": "/var/www/nextcloud/lib/public/AppFramework/Db/QBMapper.php",
        "line": 359,
        "function": "findOneQuery",
        "class": "OCP\\AppFramework\\Db\\QBMapper",
        "type": "->",
        "args": [
          {
            "__class__": "OC\\DB\\QueryBuilder\\QueryBuilder"
          }
        ]
      },
      {
        "file": "/var/www/nextcloud/apps/files_versions/lib/Db/VersionsMapper.php",
        "line": 60,
        "function": "findEntity",
        "class": "OCP\\AppFramework\\Db\\QBMapper",
        "type": "->",
        "args": [
          {
            "__class__": "OC\\DB\\QueryBuilder\\QueryBuilder"
          }
        ]
      },
      {
        "file": "/var/www/nextcloud/apps/files_versions/lib/Versions/LegacyVersionsBackend.php",
        "line": 254,
        "function": "findVersionForFileId",
        "class": "OCA\\Files_Versions\\Db\\VersionsMapper",
        "type": "->",
        "args": [
          204706,
          "*** sensitive parameters replaced ***"
        ]
      },
      {
        "file": "/var/www/nextcloud/apps/files_versions/lib/Versions/VersionManager.php",
        "line": 129,
        "function": "updateVersionEntity",
        "class": "OCA\\Files_Versions\\Versions\\LegacyVersionsBackend",
        "type": "->",
        "args": [
          "*** sensitive parameters replaced ***"
        ]
      },
      {
        "file": "/var/www/nextcloud/apps/files_versions/lib/Listener/FileEventsListener.php",
        "line": 254,
        "function": "updateVersionEntity",
        "class": "OCA\\Files_Versions\\Versions\\VersionManager",
        "type": "->",
        "args": [
          "*** sensitive parameters replaced ***"
        ]
      },
      {
        "file": "/var/www/nextcloud/apps/files_versions/lib/Listener/FileEventsListener.php",
        "line": 85,
        "function": "post_write_hook",
        "class": "OCA\\Files_Versions\\Listener\\FileEventsListener",
        "type": "->",
        "args": [
          "*** sensitive parameters replaced ***"
        ]
      },
      ...
}

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)
• Labels added where applicable (ex: bug/enhancement, 3. to review, feature component)
• Milestone added for target branch/version (ex: 32.x for stable32)

AI (if applicable)

• The test of this PR was partly or fully generated using AI