The vulnerable uuid 7.0.3 is now 11.1.1 in package-lock.json. That copy was only pulled in by xcode@3.0.1 (through the Expo config plugins in apps/mobile), which pins uuid@^7.0.3. The other copy, uuid 14.0.2 (used by mermaid), was already past the fix.
I added an npm override in package.json so that xcode takes uuid ^11.1.1. No source code imports uuid directly, so no code changes were needed. 11.x still supports the CommonJS require that xcode uses.
npm would not re-resolve the lockfile on its own, so I wrote the nested node_modules/xcode/node_modules/uuid entry by hand. The version, resolved URL and integrity hash come from npm view uuid@11.1.1. npm ci --dry-run reported no errors against the result.
I did not run the project's tests or a real install of the new lockfile. I also did not run xcode itself, so the 11.x compatibility is from reading, not from a run.