fix(game): honor original mechanism timer choices

Map detail levels 1-5 to the recovered 50, 40, 30, 20, and 10 ms callback
periods for claw animation while retaining the invariant 10 ms physics step.
This removes the hard-coded default cadence from non-default configurations.

Keep repaint batching documented separately because Rust exposes intermediate
physics states instead of reproducing Win16 GDI callback batching.

Test Plan:
- `cargo test --all-targets` -- 51 passed
- `cargo clippy --all-targets -- -D warnings` -- passed
- `cargo build --profile production` -- passed
- all five claw cadence boundary tests -- passed
- `git diff --cached --check` -- passed

tdkpin-rs/README.md

@@ -64,8 +64,9 @@ validation runs.
 | Sound | F12 | - |
 
 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 original invariant 100 Hz millipixel substep, and claw animation follows the
+recovered 50/40/30/20/10 ms timer choices. Setting-specific repaint batching
+remains a presentation-only reconstruction boundary.
 
 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