fix(physics): restore fixed-point circle responses

Replace the overlap-and-separate circle approximation with the original swept
ball-center entry test and radial/tangent fixed-point response. Preserve every
type-1 record's Real48 rebound and tangent coefficients, plus the bumper normal
kick derived from the 3800-unit speed scalar.

Unify line and circle traversal in original object-id order and remove the old
floating passive-circle and bumper impulses. Add exact tests for live object 155
and bumper 51 transitions, and keep moving flippers as the explicit remaining
collision approximation.

Test Plan:
- `cargo test --all-targets` -- 44 passed
- `cargo clippy --all-targets -- -D warnings` -- passed
- `cargo build --profile production` -- passed
- 20-second deterministic launch traversed bumpers and drained without rescue
- live object 155 and bumper 51 fixed-point transitions matched exactly
- `git diff --cached --check` -- passed

tdkpin-rs/RECONSTRUCTION.md

@@ -22,9 +22,9 @@ implementation.
 | Artwork | Exact | All 34 custom DIB images, three standard bitmaps, icon, and palette derivatives are preserved in `assets/original/`. The game uses the original 640x460 table, loading, help, ball, wheel, robot, plunger, media, and diamond frames. |
 | Audio | Exact samples | All 16 mono PCM WAV resources are embedded unchanged. Their trigger roles were recovered from resource use and gameplay context. |
 | Help and languages | Exact | Original resource images 1001-1005 are displayed directly. |
-| Playfield collision layout | Recovered | All 109 active type-2 line objects and 40 static active type-1 circles are transcribed from the original 175-object registration table. The registration routine converts its sideways inputs with `screen = (y, x - 20)` and accumulates explicitly relative objects. Type-2 records now retain every recovered Real48 normal/tangent response pair and their registered one-sided orientation. Circle sizes are complete center-contact extents, so the rendered ball radius is not added a second time. Object 174 is omitted because the original overwrites it with the live ball every frame. Moving flippers remain pending exact integration. |
+| Playfield collision layout | Recovered | All 109 active type-2 line objects and 40 static active type-1 circles are transcribed from the original 175-object registration table. The registration routine converts its sideways inputs with `screen = (y, x - 20)` and accumulates explicitly relative objects. Type-2 records retain every recovered Real48 normal/tangent response pair and registered one-sided orientation. Type-1 records retain their swept-circle radius, radial rebound, tangent coupling, and bumper kick. Object 174 is omitted because the original overwrites it with the live ball every frame. Moving flippers remain pending exact integration. |
 | Ball launcher | Recovered | The initial 32-bit fixed-point coordinates decode to `(325, 413)` in the right shooter lane. The port reproduces the initial `-375` millipixel Down event, 650 ms repeat delay, 40 ms repeats, release impulse, and randomized clamp below the original `-3800` maximum. This replaces the former guessed 330-430 px/s shot. |
-| Physics arithmetic | Partly recovered | Production movement uses the original 10 ms millipixel substep, `+15` vertical acceleration, `3800` speed bound, point-path type-2 intersection, one-sided line orientation, and Real48 normal/tangent response. Type-1 circles, type-3/4 triggers, collision-contact bookkeeping, and flipper impulses still use or coexist with floating reimplementations and remain pending. |
+| Physics arithmetic | Partly recovered | Production movement uses the original 10 ms millipixel substep, `+15` vertical acceleration, `3800` speed bound, point-path type-2 intersection, one-sided line response, and swept type-1 circle response. Live probes cover ordinary rails, ordinary circles, and a kicked bumper. Type-3/4 triggers, closest-contact selection, persistent contact bookkeeping, and flipper impulses remain pending. |
 | Rules | Partly recovered | Player count, controls, wheel holes, magnetic saves, four-position ball lock, target banks, increasing bumper value, nine-part TDK diamond, permanent double scoring for a completed diamond, KByte media progression, and media extra balls follow the original help and code paths. The claw state machine and release table are readable and terminal 18 has live differential evidence; terminals 1, 6, and 7 still need equivalent live coverage. |
 | Numeric scoring | Partly inferred | Visible 2000-6000 target values and recovered registration values are preserved. Some bumper, bank-completion, robot, wheel, lock, and media thresholds are best-evidence reconstructions because the decompiler did not recover meaningful names or a clean rule table. |
 | High scores | Compatible import | The original 276-byte table is decoded as ten `IWIK`-XOR-obfuscated little-endian scores plus ten 22-byte names, sorted, then migrated to portable JSON. |