[FE-08] Replace all any types in API layer with strict interfaces and Zod runtime validation

[Leothosine]

Problem

frontend/lib/api/admin.ts uses the any type for updateProfile (line 149), getAnalytics (line 201), and several mutation return values. useQuery and useMutation calls throughout the codebase lack generic type parameters. If the backend changes a response shape, TypeScript gives no compile-time warning - runtime errors surface deep inside component render logic.

Proposed Solution

1. Create frontend/lib/types/api.ts with strict response interfaces for every endpoint: DashboardStatsResponse, MenuItemResponse, AdminUserResponse, GalleryImageResponse, ContactSubmissionResponse, AnalyticsResponse
2. Create a discriminated union for API errors: type ApiError = { statusCode: number; message: string; details?: Record<string, string[]> }
3. Add Zod schemas for the 5 most critical responses and validate them in the API client
4. Apply React Query generics: useQuery<MenuItemResponse[], ApiError>()
5. Enable noImplicitAny in tsconfig.json

Acceptance Criteria

• Zero uses of any type in frontend/lib/api/
• TypeScript compile error if a component accesses a field not in the response interface
• A mismatched backend response throws a ZodError with the field name before reaching component state
• noImplicitAny: true in tsconfig.json
• All useQuery / useMutation calls have explicit generic type parameters

[AbdulmujibOladayo]

Hi Maintainer, i can handle this very efficiently. Kindly help assign. i will resolve it in an eta of 1 day.

[grantfox-oss]

🦊 GrantFox — @AbdulmujibOladayo has been assigned to this issue as part of the Official Campaign | FWC26 campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #276)
2. Your PR will be reviewed by the tosirano maintainers

Good luck! Track your progress on GrantFox.

[grantfox-oss]

🎉 This issue has been marked as completed on GrantFox as part of the Official Campaign | FWC26 campaign!

@AbdulmujibOladayo's PR #301 was approved and merged by @Leothosine.

🏆 @AbdulmujibOladayo: You earned 35 FoxPoints for this contribution! Your current tier: Explorer (939 total points). Track your full progress on GrantFox.

👏 Great work, @AbdulmujibOladayo! Keep contributing to tosirano.