Add interactive post-session review

[PurpleSentinel]

Summary

• retain bounded total and directional G peaks for each track session
• include launch-detection samples without adding IMU reads
• show session time, overrun, maximum G, acceleration, braking, left G, right G, and completion reason on eight separate high-visibility pages
• use left/right swipe navigation and require advancement from the final page before cool-down begins
• preserve captured values as partial data after a late IMU failure and keep normal timing available without the IMU
• document the review flow, mounting convention, and deployment module

Why

The original dense, timed summary did not give the driver enough control or make each result sufficiently visible on the 240×240 round display. The interactive review gives every result the full screen and prevents the cool-down transition until the driver has reached the final result.

Session results remain bounded in RAM only. Persistent history, deletion, retention, and export remain future work under the existing roadmap issues.

Validation

• python3 -m unittest discover -s tests — 165 tests pass
• Python compilation and git diff --check pass
• all eight pages fit the circular display safe area in host tests
• all eight pages rendered successfully on the supported RP2040 hardware
• explicit page-transition collection retained roughly 56–58 KB free heap during the hardware page cycle
• firmware rebooted successfully into normal Timer operation

Progresses #39.
Progresses #48.