Dashboard memory leak when using auto-refresh

Describe the bug

When auto-refresh is used (and potentially when not), the tab that has the dashboard open has constantly escalating memory usage until either the tab or browser crashes. Reproducible on at least Firefox and iOS Safari.

To Reproduce

1. Open a dashboard
2. Turn on auto refresh in the top right
3. Edit the #refresh=x in the URL to be #refresh=1 to accelerate the memory leak by refreshing every second. This is optional, the memory leaks even at lower refresh rates.
4. Observe the tab memory usage increasing (use Firefox dev tools 'Memory' tab or look in your OS activity monitor equivalent or just wait for the page to eventually crash (depending on how much RAM you have))
5. Optional: Do memory snapshots in browser dev tools, compare and observe that there is an increasing number of retained Arrays/Objects.

Expected behavior

Memory usage should not continually grow; the data needed to render the previous refreshes should not be retained.

Logs

Browser console is empty

Information about your Metabase installation

{
  "browser-info": {
    "language": "en-GB",
    "platform": "Linux x86_64",
    "userAgent": "Mozilla/5.0 (X11; Linux x86_64; rv:156.0) Gecko/20100101 Firefox/156.0",
    "vendor": ""
  },
  "metabase-info": {
    "databases": [
      "postgres"
    ],
    "run-mode": "prod",
    "plan-alias": "",
    "version": {
      "date": "2026-07-31",
      "tag": "v0.63.2.7",
      "hash": "30c5762"
    },
    "settings": {
      "report-timezone": null
    },
    "hosting-env": "unknown",
    "application-database": "h2",
    "application-database-details": {
      "database": {
        "name": "H2",
        "version": "2.1.214 (2022-06-13)"
      },
      "jdbc-driver": {
        "name": "H2 JDBC Driver",
        "version": "2.1.214 (2022-06-13)"
      }
    }
  },
  "system-info": {
    "file.encoding": "UTF-8",
    "java.runtime.name": "OpenJDK Runtime Environment",
    "java.runtime.version": "25.0.3+9-LTS",
    "java.vendor": "Eclipse Adoptium",
    "java.vendor.url": "https://adoptium.net/",
    "java.version": "25.0.3",
    "java.vm.name": "OpenJDK 64-Bit Server VM",
    "java.vm.version": "25.0.3+9-LTS",
    "jvm.available-processors": 4,
    "jvm.max-memory": "7.8 GB",
    "os.name": "Linux",
    "os.version": "6.1.0-26-amd64",
    "system.total-memory": "31.3 GB",
    "user.language": "en",
    "user.timezone": "GMT"
  }
}

Severity

Annoying (Browser tab crash)

Additional context

No response