Replace useState(null as T) casts on the API keys page with typed generics

[mikewheeleer]

Clean up the loose typing on the API keys page

Description

src/app/api-keys/page.tsx declares state with useState(null as KeyItem[] | null) and casts apiGet results with (b as { items: KeyItem[] }).items and (res as { key: string }).key, bypassing the generic typing that src/lib/apiClient.ts provides (apiGet<T>/apiPost<T>). This is inconsistent with the rest of the codebase (e.g. webhooks uses apiGet<{ items: Webhook[] }>) and weakens type safety. This issue tightens the typing without changing behaviour.

Requirements and context

• Repository scope: Agentpay-Org/Agentpay-frontend only.
• Replace useState(null as …) with the generic form useState<… | null>(null).
• Use apiGet<{ items: KeyItem[] }> and apiPost<{ key: string }> so the as casts can be removed.
• Do not change any rendered behaviour, the reveal/copy/revoke flows, or the API paths.
• Keep the file passing lint with no new any/unsafe casts.

Suggested execution

• Fork the repo and create a branch
• git checkout -b refactor/api-keys-typed-state
• Implement changes
  • Write code in: src/app/api-keys/page.tsx.
  • Write comprehensive tests in: ensure src/app/api-keys/page.test.tsx still passes; add an assertion that create returns the typed key.
  • Add documentation: none beyond a short JSDoc on any extracted type if needed.
  • Validate npm run typecheck passes with no casts removed losing safety.
• Test and commit

Test and commit

• Run npm run lint, npm run typecheck, npm test, and npm run build.
• Cover edge cases: create success, list load, and revoke — all unchanged.
• Include the npm test output.

Example commit message

refactor(api-keys): use typed apiClient generics instead of as-casts

Guidelines

• Minimum 95 percent test coverage for the changed page.
• Clear, reviewer-focused documentation.
• Timeframe: 96 hours.

Community & contribution rewards

• 💬 Join the AgentPay community on Discord for questions, reviews, and faster merges: https://discord.gg/eXvRKkgcv
• ⭐ This is a GrantFox OSS / Official Campaign task and may be rewarded. When your PR is merged you'll be prompted to rate the project — if this issue and the maintainers helped you ship, we'd be grateful for a 5-star rating. Clear questions in Discord and tidy, well-tested PRs are the fastest path to a merge and a reward.

[gloskull]

Hello, I have 4 years of experience delivering solutions for projects like this, covering backend, frontend, and smart contract development. After carefully reviewing your requirements, I have a clear understanding of the task and am confident in my ability to deliver a clean, efficient, and thoroughly tested solution on time. I prioritize code quality, maintainability, and industry best practices throughout the development process.
My PR will be submitted in under 10hours.