Add tests for the useLocalState hook including SSR-safe hydration

[mikewheeleer]

Test the useLocalState hook hydration and write paths

Description

src/lib/useLocalState.ts backs state with localStorage and swallows JSON parse/write errors, but it has no test coverage — the hydration effect, the malformed-JSON fallback, and the write-through behaviour are all unverified. This issue adds a test suite mirroring the style of src/lib/__tests__/useDebounce.test.tsx.

Requirements and context

• Repository scope: Agentpay-Org/Agentpay-frontend only.
• Assert: initial value is the fallback before hydration, the stored value is read after the effect, write updates both state and localStorage, and malformed stored JSON falls back without throwing.
• Use a real or mocked window.localStorage; clear it between tests.
• Cover the try/catch branches that currently /* ignore */.

Suggested execution

• Fork the repo and create a branch
• git checkout -b test/testing-16-uselocalstate
• Implement changes
  • Write comprehensive tests in: create src/lib/__tests__/useLocalState.test.tsx.
  • Add documentation: none beyond test descriptions.
  • Validate no act() warnings and deterministic teardown.
• Test and commit

Test and commit

• Run npm run lint, npm run typecheck, and npm test.
• Cover edge cases: missing key, corrupt JSON, and a setItem throw (quota) being swallowed.
• Include the npm test output and the coverage summary for the hook.

Example commit message

test(lib): cover useLocalState hydration, write-through, and error fallbacks

Guidelines

• Minimum 95 percent test coverage for useLocalState.ts.
• 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.