Chore/lint cleanup

[TheBigWealth89]

Fix ESLint and TypeScript Violations

Resolves #184

Summary

This PR cleans up the frontend codebase to resolve all ESLint and TypeScript errors, strictly adhering to type safety without introducing any or blindly silencing errors. The repository now passes all linting and type-checking out-of-the-box.

Before → After

• ESLint: 2 errors → 0 errors
• TypeScript: 0 errors → 0 errors
• Strict Mode: Confirmed "strict": true is active in tsconfig.json.

Changes & Fixes

• Config Fix: Added missing eslint-plugin-react-hooks definition to eslint.config.mjs which was causing the react-hooks/exhaustive-deps rule to crash the linter.
• Removed Unused Variable: Removed the unused mockContainerRef from tests/hooks/useVirtualList.test.ts.
• Cleaned Up Directives: Removed an unnecessary // eslint-disable-next-line react-hooks/exhaustive-deps from src/hooks/useVirtualList.ts that was flagged as unused by ESLint once the config was fixed.
• Added Script: Added "typecheck": "tsc --noEmit" to package.json to make CI verification easier.

Exceptions / Review Notes

• Maintained the existing tsEslint.configs.recommended config rather than upgrading to recommendedTypeChecked. Attempting the latter surfaced 244 test-related unsafe assignment errors which is well beyond the scope of a standard lint cleanup for this codebase.
• 4 unit tests currently fail locally (VirtualList, setupDev, preCommit), but they were verified as unrelated to the linting changes (zero application logic was modified). These should be tracked down in a follow-up test hygiene PR.

Commits

• fix(lint): resolve no-unused-vars and exhaustive-deps config
• chore(config): enable strict mode and tidy eslint config