fix(game): restore the original plunger launch

Start each ball at the recovered right-lane coordinates and charge the
plunger while Down is held, firing only on release. Render all eleven frames
of resource 901, preserve object 25 as the returning-ball catch, and use the
object table's center-contact extents without adding the art radius twice.

Test Plan:
- cargo fmt --all -- --check
- cargo test
- cargo clippy --all-targets --all-features -- -D warnings
- runtime smoke: start, hold Down, release, and inspect the right shooter lane

tdkpin-rs/RECONSTRUCTION.md

@@ -19,10 +19,11 @@ implementation.
 
 | Subsystem | Rust status | Evidence and boundary |
 | --- | --- | --- |
-| 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, magnet, media, and diamond frames. |
+| 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. Object 174 is omitted because the original overwrites it with the live ball every frame. Moving flippers use equivalent native Rust bodies. |
+| 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. Its 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 use equivalent native Rust bodies. |
+| Ball launcher | Recovered | The initial 32-bit fixed-point coordinates decode to `(325, 413)` in the right shooter lane. Scan code `0x50` compresses the eleven frames in resource 901 while Down is held; the key-release routine activates the ball with the accumulated vertical launch velocity. |
 | Physics arithmetic | Reimplemented | The Win16 fixed-point/timer engine is replaced by deterministic fixed-step floating-point integration. Restitution and impulses are tuned to the recovered table but are not instruction-for-instruction equivalents. |
 | Rules | Behaviorally recovered | Player count, controls, wheel holes, magnetic saves, robot grip, 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. |
 | 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. |