fix(physics): restore standard tangent sign response

The left relative slingshot probe proved the spin projection, but its geometry
did not distinguish the sign rule. A stopped-Wine probe on symmetric record 72
did: the binary uses the standard dot-product tangent for both spin and the
opposing direction of the current tangential response. The earlier
swapped-component interpretation happened to agree for vertical walls and a
centered circle but selected the wrong sign on the right slingshot.

Use `tv=(vx*nx+vy*ny)/length`, update spin with
`tv*0.02*response_tangent`, and apply
`-sign(tv)*abs(normal_velocity)*response_tangent`, retaining the binary's
negative direction when tv is zero. Seal record 72's exact position, velocity,
and `+5.46` Real48 spin in C and Rust. Keep the two-minute autoplay assertion
focused on actual launch, press/release, target, bumper, and finite-state
activity after the corrected trajectory.

Test Plan:
- stopped Wine 11.15 record-72 injection/trace -- matched position, velocity, and spin
- `cargo test --workspace --all-targets --all-features` -- 124 passed
- `cargo clippy --workspace --all-targets --all-features -- -D warnings` -- passed
- `bash original/tools/test_reconstructed_c.sh` -- passed
- `python3 original/tools/audit_reconstruction.py --require-complete` -- passed with zero incomplete or unclassified units
- `rumdl check --flavor commonmark RECONSTRUCTION.md CHANGELOG.md` -- passed
- `git diff --cached --check` -- passed

tdkpin-rs/CHANGELOG.md

@@ -10,11 +10,13 @@ and this project adheres to
 
 ### Fixed
 
-- Separate the common response's two binary projections: the swapped-component
-  value supplies the sign of `abs(normal_velocity)*response_tangent`, while
-  `(vx*nx+vy*ny)/length * 0.02 * response_tangent` updates spin. Live probes now
+- Restore the common response's standard dot-product tangent
+  `tv=(vx*nx+vy*ny)/length`: `tv*0.02*response_tangent` updates spin, while the
+  current response opposes its sign with magnitude
+  `abs(normal_velocity)*response_tangent` (negative when `tv==0`). Live probes
   match horizontal drain `(-302,-1809)`, ordinary circle `(94,564)`, bumper
-  `(197,3096)`, and relative record 57 `(1839,1832)` with spin exactly `-5.28`.
+  `(197,3096)`, relative record 57 `(1839,1832)` with spin `-5.28`, and record
+  72 `(-2095,1669)` with spin `+5.46`.
 - Gate dynamic record 174/175 impulse transfer on the other slot's capture age:
   a held ball remains velocity-stationary and the moving response retains its
   full normal velocity instead of always subtracting 1,000.
@@ -74,7 +76,8 @@ and this project adheres to
   flagless TDK companion lines also retain their zero contact/link field rather
   than carrying unused synthetic head IDs. Record 57 additionally matches the
   live original's `(75530,354765)/(3000,15)` to
-  `(77369,356597)/(1839,1832)` transition.
+  `(77369,356597)/(1839,1832)` transition; symmetric record 72 matches
+  `(235348,356825)/(-3000,15)` to `(233253,358494)/(-2095,1669)`.
 - Match rectangular type-4 magnetic gates to raw `1000:9b69`: enter only when
   the previous position is inside, then deactivate when the newly predicted
   position exits any edge, replacing a swept-intersection approximation.