Nextjs 16 Upgrade (2/4) - Run npm audit fix

[mintybasil]

Description

Related to #368.

This PR is stacked on #457, which must be merged first.

Runs npm audit fix to remove some vulnerable dependencies.

Before - 29 vulnerabilities (2 low, 10 moderate, 16 high, 1 critical)
After - 15 vulnerabilities (1 low, 5 moderate, 8 high, 1 critical)

Testing instructions

Same as previous PR, for good measure:

npm install
npx next typegen
npm run lint

docker compose up --detach --wait
npm run db:run-migrations  
npm run tsxe src/scripts/updateDatabase.ts  
npm run tsxe src/scripts/repopulateRawContactsAndVotes.ts  
npm run dev:html  
npm run preview

Checklist

• This PR addresses all requirements described in the issue
• I have commented my code, particularly in hard-to-understand areas ✅ 2026-07-09
• I have performed a self-review of my code ✅ 2026-07-09
• I have tested these changes in my local environment ✅ 2026-07-09
• I have tested these changes in the preview site generated by this PR (you must finish opening the PR first)
• I have made corresponding changes to the documentation (if relevant) ✅ 2026-07-09

[github-actions]

🚀 Preview URL for this PR: https://ab48439a-civic-dashboard-web.civic-dashboard.workers.dev