Add nao newsletter subscription in account settings

[ClaireGz]

Summary

• Adds a "nao Newsletter" row in Settings > Account > General Settings that lets logged-in users subscribe to the nao newsletter.
• Calls the same https://sunshine.getnao.io/api/waitlist/ endpoint as the "Keep me updated" form on the getnao.io website footer, so signups land in the same database.
• Persists subscription state in localStorage so the row shows a "Subscribed" check after signing up.

Changes

• New component: `apps/frontend/src/components/settings/newsletter-subscription.tsx`
• Wired into the Account settings page next to the Theme selector
• Added a search index entry so it shows up in settings search

Test plan

• Visit `/settings/account`, click Subscribe — confirm "You're subscribed!" message and the row switches to a "Subscribed" check
• Click subscribe again with the same email — confirm "You're already subscribed!" handling
• Verify the entry appears when searching "newsletter" in the settings search

🤖 Generated with Claude Code

Related issue

#570

[cubic-dev-ai]

1 issue found across 3 files

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="apps/frontend/src/components/settings/newsletter-subscription.tsx">

<violation number="1" location="apps/frontend/src/components/settings/newsletter-subscription.tsx:9">
P2: Subscription state is stored in a global localStorage key, so it can leak across different user accounts on the same browser.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[github-actions]

🚀 Preview Deployment

URL	https://pr-721-10ccd1d.preview.getnao.io
Commit	10ccd1d

⚠️ No LLM API keys configured - you'll see the API key setup flow when trying to chat.

---

_{Preview will be automatically removed when this PR is closed.}

[cubic-dev-ai]

1 issue found across 1 file (changes from recent commits).

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="apps/frontend/src/components/settings/newsletter-subscription.tsx">

<violation number="1" location="apps/frontend/src/components/settings/newsletter-subscription.tsx:14">
P2: `subscribed` can become stale when `email` changes because `useLocalStorage` does not re-read from the new storage key. This can show the wrong subscription state until a reload.</violation>
</file>

_{Tip: Review your code locally with the cubic CLI to iterate faster.}