Multi party approval UI] create use mutate approval decision hook

[oyinade247]

closes #177

PR: Implement Approval Decision Mutation Hook

Summary
This PR implements the useMutateApprovalDecision hook, which allows users to submit approval or rejection decisions for an adoption. It features optimistic UI updates for zero-latency feedback and automatic rollback on server errors.

Key Changes

• Hook: useMutateApprovalDecision(adoptionId) handles state, optimistic updates, and invalidation.
• Optimistic UI: Immediately updates the approvals list to reflect the user's decision.
• Rollback: Leverages useApiMutation snapshots to restore cache state if the request fails.
• Invalidation: Clears adoption, approvals, and timeline queries on success to ensure data consistency.
• API: Added approveAdoption method to adoptionService.
• Testing: Comprehensive Vitest suite for all mutation phases (optimistic, success, failure).

Verification Proof

• Unit Tests: All 3 mutation tests passed.
• Visuals: Verified via /preview-approval showing instant UI response and success toast.

[amina69]

@oyinade247 conflict

[amina69]

@oyinade247 build failed