chore: upgrade dompurify to ^3.4.9 to address CVE-2026-49978

Refresh the dompurify lockfile entry (transitive via posthog-js, range
^3.3.2) from 3.4.0 to 3.4.11, which covers CVE-2026-49978 (IN_PLACE
sanitization bypass via shadow root inside <template>.content).

Generated with [Linear](https://linear.app/sourcebot/issue/SOU-1348/sourcebot-devsourcebot-cve-2026-49978-dompurify-in-place-sanitization#agent-session-a400c836)

Co-authored-by: linear-code[bot] <222613912+linear-code[bot]@users.noreply.github.com>

Author: brendan-kellam

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
 - Upgraded `@grpc/grpc-js` to `^1.14.4`. [#1315](https://github.com/sourcebot-dev/sourcebot/pull/1315)
 - Upgraded `vite` to `^8.0.16`. [#1313](https://github.com/sourcebot-dev/sourcebot/pull/1313)
+- Upgraded `dompurify` to `^3.4.9`. [#1325](https://github.com/sourcebot-dev/sourcebot/pull/1325)
 
 ## [5.0.3] - 2026-06-17
 

yarn.lock

@@ -13127,14 +13127,14 @@ __metadata:
   linkType: hard
 
 "dompurify@npm:^3.3.2":
-  version: 3.4.0
-  resolution: "dompurify@npm:3.4.0"
+  version: 3.4.11
+  resolution: "dompurify@npm:3.4.11"
   dependencies:
     "@types/trusted-types": "npm:^2.0.7"
   dependenciesMeta:
     "@types/trusted-types":
       optional: true
-  checksum: 10c0/5593ac44ee20b9aa521c2120884effc98927fb9128c548183c75e79e0a04357c62ee913a049a267c8f396cb8c9d520ecf72562826c5524c46d4fe03c12063638
+  checksum: 10c0/31439481c7e8fc3805d40c376936fd66936620fb1b1a31a2ec097f6165412c37f2d868e082c9ceba62bb37661c1ea132a5db4d5213434317e30df68d4aca9cc9
   languageName: node
   linkType: hard