fix(physics): restore fixed-point rail movement

Replace the guessed variable-rate floating integration with the original 10 ms
millipixel step, 15-unit gravity, and 3800-unit speed limit. Restore every
registered type-2 Real48 response pair, one-sided start-to-end orientation, and
the original normal/tangent velocity transform validated against live shooter
wall traces.

Restore repeat-driven plunger charging and its release-time randomized clamp.
The shooter route now follows table orientation instead of coordinate-specific
gate exceptions. Remove the synthetic ball-search impulse so future stuck balls
remain visible reconstruction failures, and include collision ids in deterministic
traces for differential work on circles and triggers.

Test Plan:
- `cargo test --all-targets` -- 42 passed
- `cargo clippy --all-targets -- -D warnings` -- passed
- `cargo build --profile production` -- passed
- charged launcher scenario cleared the shooter lane -- passed
- all recovered rails accepted front-side and rejected back-side probes
- `git diff --cached --check` -- passed

tdkpin-rs/README.md

@@ -61,8 +61,9 @@ and `claw-18`; `--seed N` fixes random choices for later seeded scenarios.
 | High scores | F3 | - |
 | Sound | F12 | - |
 
-The five original speed choices are retained as simulation-detail settings.
-They change fixed-step resolution without changing the speed of play.
+The five original speed choices remain available in settings. Physics now uses
+the original invariant 100 Hz millipixel substep; exact setting-specific timer
+batching for presentation and mechanism animation remains under reconstruction.
 
 The help screen is the original artwork in English, German, French, Italian,
 or Spanish. As instructed on that screen, double-clicking its upper-left exit