No test for concurrent tipping from multiple users to verify state consistency

[Mosas2000]

Description

The current tests use a linear sequence of operations. In production, multiple users will send tips in the same block. There are no tests that simulate concurrent operations to verify that the state (total-tips-sent, total-volume, user counts) remains consistent when multiple tips happen in sequence within a test.

File

tests/tipstream.test.ts

Suggested Fix

Write a test that has wallet1 tip wallet2, wallet2 tip wallet3, and wallet3 tip wallet1 in rapid succession, then verify all user stats and platform stats are correct. This validates that the contract handles sequential state updates without conflicts.