Build a self-contained observation hook on the starter's base hook: on each swap it appends the pool's current tick and the block number to a fixed-size ring buffer keyed by pool, and exposes …

Build a self-contained observation hook on the starter's base hook: on each swap it appends the pool's current tick and the block number to a fixed-size ring buffer keyed by pool, and exposes read-only views for the most recent entry and for the buffer's contents in order.

It takes no fee, holds no privileged role, stores no owner or admin, and extends nothing that already exists — the buffer size is a compile-time constant of the contract, not a configurable economic parameter. The independent tester should exercise the paths the implementer would rather avoid: reads before any swap has ever happened, several swaps within a single block, wraparound once the buffer is full, and two pools writing without seeing each other's entries.

Use the harness that hands the hook a real launch pool rather than mocking the manager.