fix(physics): restore relative slingshot response

A full comparison against the 175-record ledger found stale guessed coordinates
in both relative slingshot chains. Circles 56/58/71/73 and lines 57/59/72/74
were displaced by up to 70 pixels. The corrected record-57 geometry then
exposed a second issue: readable C and Rust had collapsed two independent
binary response projections into one.

Transcribe the accumulated initializer coordinates exactly. Use the
swapped-component projection only to sign the current tangential response
`abs(normal_velocity) * response_tangent`, and use the standard dot product for
`spin_delta * 0.02 * response_tangent`. Correct the readable C evidence and
Rust together, extend live tracing with the six-byte spin field, and seal the
stopped-Wine transition from `(75530,354765)/(3000,15)` to
`(77369,356597)/(1839,1832)` with Real48 spin `-5.28` in both harnesses.

Test Plan:
- stopped Wine 11.15 record-57 injection/trace -- matched position, velocity, and spin
- `cargo test --workspace --all-targets --all-features` -- 123 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
- `python3 -m py_compile original/tools/trace_original_state.py original/tools/inject_original_state.py` -- passed
- `rumdl check --flavor commonmark RECONSTRUCTION.md CHANGELOG.md` -- passed
- `git diff --cached --check` -- passed

original/tools/inject_original_state.py

@@ -21,6 +21,7 @@ from trace_original_state import (
     PHYSICS_SUBSTEPS,
     PREVIOUS_BALL_X,
     PREVIOUS_BALL_Y,
+    SPIN_REAL48,
     VELOCITY_X,
     VELOCITY_Y,
     ProcessMemory,
@@ -139,7 +140,8 @@ def main() -> None:
             memory.write(object_base + BALL_SUSPENDED, bytes(1))
             print(
                 f"TDKPIN pid={pid} data={data_base:#x} object={object_base:#x} "
-                f"ball=({args.x:.3f},{args.y:.3f}) velocity=({args.vx:.3f},{args.vy:.3f})"
+                f"ball=({args.x:.3f},{args.y:.3f}) velocity=({args.vx:.3f},{args.vy:.3f}) "
+                f"spin={int.from_bytes(memory.read(object_base + SPIN_REAL48, 6), 'little'):#014x}"
             )
     finally:
         if resume_afterward:

original/tools/trace_original_state.py

@@ -39,6 +39,7 @@ GRAVITY_PER_SUBSTEP = 0x005A
 ACTIVE_BALL_COUNT = 0x0061
 VELOCITY_X = 0x0BAA
 VELOCITY_Y = 0x0BAE
+SPIN_REAL48 = 0x0BCE
 PREVIOUS_BALL_X = 0x0BBA
 PREVIOUS_BALL_Y = 0x0BBE
 OBJECT_BALL_X = 0x0BC2
@@ -224,6 +225,7 @@ CSV_FIELDS = [
     "next_ball_y_milli",
     "velocity_x_milli_per_tick",
     "velocity_y_milli_per_tick",
+    "spin_real48_bits",
     "previous_ball_x_milli",
     "previous_ball_y_milli",
     "object_ball_x_milli",
@@ -257,6 +259,7 @@ def sample_state(data: bytes, obj: bytes) -> tuple[int, ...]:
         unpack_i32(data, NEXT_BALL_Y),
         unpack_i32(obj, VELOCITY_X),
         unpack_i32(obj, VELOCITY_Y),
+        int.from_bytes(obj[SPIN_REAL48 : SPIN_REAL48 + 6], "little"),
         unpack_i32(obj, PREVIOUS_BALL_X),
         unpack_i32(obj, PREVIOUS_BALL_Y),
         unpack_i32(obj, OBJECT_BALL_X),