chore(deps-dev): bump postcss from 8.5.16 to 8.5.26 in /client

Bumps [postcss](https://github.com/postcss/postcss) from 8.5.16 to 8.5.26.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.5.16...8.5.26)

---
updated-dependencies:
- dependency-name: postcss
  dependency-version: 8.5.25
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

client/package-lock.json

@@ -108,7 +108,7 @@
     "fake-indexeddb": "^6.2.5",
     "jsdom": "^29.1.1",
     "oxlint": "^1.71.0",
-    "postcss": "^8.5.16",
+    "postcss": "^8.5.26",
     "tailwindcss": "^3.4.19",
     "typescript": "~6.0.2",
     "vite": "^8.1.1",