THE STRIDE GATE: a walk cycle is one drawing with the legs moved, and now something checks

Oliver, on the sprites, again: "when people on a tennis court walk or run their
legs move... this pattern is almost always failing." It has failed repeatedly
because NOTHING IN THE PIPELINE MEASURED IT. Frame count, magenta background,
clipped edges and detail density all pass cleanly on two unrelated
illustrations of the same character, which is exactly what the generator
produces when asked for "the same frame with the other leg forward".

Three numbers per declared pair, silhouette only, on the feet-aligned centred
overlay drawStatic actually draws:
  HGT  height ratio — off 1.00 means the body grows and shrinks once per step
  TOP  difference ABOVE the hip — near zero for a real pair: same man, same camera
  LEG  difference BELOW it — this is the step
Calibrated on the pairs that read (brute wound lurch 1.00/0.000/0.638, shambler
1.00/0.070/0.520) against the ones that do not (TOP 0.47-0.85, or LEG 0.09).
Opt-in per batch via `stride: [[i, j]]`, because the player's four-frame RUN
sits at TOP 0.23 and is right — a run swings the arms too.

`--audit` runs the same gate over the sprites ALREADY INSTALLED and exits
non-zero on a failure: a gate that only fires on new rolls says nothing about
the art already in the game, which is where this was noticed. Five of the six
racket pairs fail it today.

And the kit gate, which already existed and was never switched on here: Oliver
spotted the headless men's trousers had changed colour. Measured — the headless
set's near-white fraction DOUBLES (9.5 -> 19.5) where losing a head only
accounts for ~1.3 of that, and the wounded swing drifted the other way (shorts
60.5 against its own stage's 85). palette_ref + a per-batch tolerance now catch
all three drifted sets and pass the one that looked right.

Fixed while in there, mine from the last commit: the wounded stride stepped off
walkT, a wall clock, while the healthy one steps off ground covered — the exact
foot-slide this project banned for the heavy bodies.

No art regenerated yet: the gate and the audit come first, so a re-roll can be
told from a lucky one.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

assets/_regen_batches.json

@@ -1135,7 +1135,13 @@
   "state": true,
   "check": "same",
   "anchor": 0,
-  "subject": "Four frames of the ZOMBIE TENNIS PLAYER shown in the FIRST reference image — the same dead man: yellow hair, red headband, red shirt, grey shorts, grey-green corpse skin, sunken eyes, a wooden racket in his hand. The OTHER reference images are a LIVING tennis player and are there ONLY to show the POSES to copy — never the character, never the clothes, never the skin. HIS KIT IS FIXED AND MUST BE IDENTICAL IN EVERY FRAME: dirty yellow-blond hair, a RED CLOTH HEADBAND tied round his forehead, a torn red short-sleeved tennis shirt, SHORT GREY TENNIS SHORTS ENDING ABOVE THE KNEE (never long trousers), bare grey-green dead legs below them, white socks and white tennis shoes, and a wooden racket with a pale strung head. Frame 1: the READY STANCE — copy the pose of reference image 2 exactly: knees bent, weight forward on the toes, the racket held UP in front of the body in both hands, chest and face square to the viewer, waiting to return a serve. Frame 2: a SIDE SHUFFLE STEP toward the viewer — copy the legs of reference image 3, left leg driving out, the racket still held up ready in front. Frame 3: the same shuffle with the RIGHT leg driving out instead — identical to frame 2 in every other respect, only the legs swapped. Frame 4: a FOREHAND SWING at the moment of contact — copy the pose of reference image 4 exactly: the body rotated, the arm extended across, the racket head out to the side at waist height, weight on the front foot. Output exactly 4 figures side by side in ONE horizontal row, all the same height. "
+  "subject": "Four frames of the ZOMBIE TENNIS PLAYER shown in the FIRST reference image — the same dead man: yellow hair, red headband, red shirt, grey shorts, grey-green corpse skin, sunken eyes, a wooden racket in his hand. The OTHER reference images are a LIVING tennis player and are there ONLY to show the POSES to copy — never the character, never the clothes, never the skin. HIS KIT IS FIXED AND MUST BE IDENTICAL IN EVERY FRAME: dirty yellow-blond hair, a RED CLOTH HEADBAND tied round his forehead, a torn red short-sleeved tennis shirt, SHORT GREY TENNIS SHORTS ENDING ABOVE THE KNEE (never long trousers), bare grey-green dead legs below them, white socks and white tennis shoes, and a wooden racket with a pale strung head. Frame 1: the READY STANCE — copy the pose of reference image 2 exactly: knees bent, weight forward on the toes, the racket held UP in front of the body in both hands, chest and face square to the viewer, waiting to return a serve. Frame 2: a SIDE SHUFFLE STEP toward the viewer — copy the legs of reference image 3, left leg driving out, the racket still held up ready in front. Frame 3: the same shuffle with the RIGHT leg driving out instead — identical to frame 2 in every other respect, only the legs swapped. Frame 4: a FOREHAND SWING at the moment of contact — copy the pose of reference image 4 exactly: the body rotated, the arm extended across, the racket head out to the side at waist height, weight on the front foot. Output exactly 4 figures side by side in ONE horizontal row, all the same height. ",
+  "stride": [
+   [
+    1,
+    2
+   ]
+  ]
  },
  "racket_w1": {
   "sprites": [
@@ -1152,7 +1158,19 @@
   "state": true,
   "check": "same",
   "anchor": 0,
-  "subject": "Three frames of the ZOMBIE TENNIS PLAYER shown in the FIRST reference image — the same dead man: yellow hair, red headband, red shirt, grey shorts, grey-green corpse skin, sunken eyes, a wooden racket in his hand. The OTHER reference images are a LIVING tennis player and are there ONLY to show the POSES to copy — never the character, never the clothes, never the skin. In ALL THREE frames his LEFT arm — the one WITHOUT the racket — has been torn off at the shoulder and the stump is gushing blood down his side, and his shirt is slashed open across the ribs. He still swings the racket with his remaining arm. HIS KIT IS FIXED AND MUST BE IDENTICAL IN EVERY FRAME: dirty yellow-blond hair, a RED CLOTH HEADBAND tied round his forehead, a torn red short-sleeved tennis shirt, SHORT GREY TENNIS SHORTS ENDING ABOVE THE KNEE (never long trousers), bare grey-green dead legs below them, white socks and white tennis shoes, and a wooden racket with a pale strung head. Frame 1: a SIDE SHUFFLE STEP toward the viewer — copy the legs of reference image 3, left leg driving out, the racket still held up ready. Frame 2: the same shuffle with the RIGHT leg driving out instead, identical otherwise. Frame 3: a FOREHAND SWING at the moment of contact — copy the pose of reference image 4: body rotated, the racket head out to the side at waist height. Output exactly 3 figures side by side in ONE horizontal row, all the same height. "
+  "subject": "Three frames of the ZOMBIE TENNIS PLAYER shown in the FIRST reference image — the same dead man: yellow hair, red headband, red shirt, grey shorts, grey-green corpse skin, sunken eyes, a wooden racket in his hand. The OTHER reference images are a LIVING tennis player and are there ONLY to show the POSES to copy — never the character, never the clothes, never the skin. In ALL THREE frames his LEFT arm — the one WITHOUT the racket — has been torn off at the shoulder and the stump is gushing blood down his side, and his shirt is slashed open across the ribs. He still swings the racket with his remaining arm. HIS KIT IS FIXED AND MUST BE IDENTICAL IN EVERY FRAME: dirty yellow-blond hair, a RED CLOTH HEADBAND tied round his forehead, a torn red short-sleeved tennis shirt, SHORT GREY TENNIS SHORTS ENDING ABOVE THE KNEE (never long trousers), bare grey-green dead legs below them, white socks and white tennis shoes, and a wooden racket with a pale strung head. Frame 1: a SIDE SHUFFLE STEP toward the viewer — copy the legs of reference image 3, left leg driving out, the racket still held up ready. Frame 2: the same shuffle with the RIGHT leg driving out instead, identical otherwise. Frame 3: a FOREHAND SWING at the moment of contact — copy the pose of reference image 4: body rotated, the racket head out to the side at waist height. Output exactly 3 figures side by side in ONE horizontal row, all the same height. ",
+  "stride": [
+   [
+    0,
+    1
+   ]
+  ],
+  "palette_ref": "z_r1",
+  "palette_tol": [
+   12,
+   10,
+   6
+  ]
  },
  "racket_w2": {
   "sprites": [
@@ -1169,7 +1187,19 @@
   "state": true,
   "check": "same",
   "anchor": 0,
-  "subject": "Three frames of the ZOMBIE TENNIS PLAYER shown in the FIRST reference image — the same dead man: yellow hair, red headband, red shirt, grey shorts, grey-green corpse skin, sunken eyes, a wooden racket in his hand. The OTHER reference images are a LIVING tennis player and are there ONLY to show the POSES to copy — never the character, never the clothes, never the skin. In ALL THREE frames he is HEADLESS: his head is gone entirely and the neck is a ragged gushing stump, so this figure is A CLEAR HEAD SHORTER than a whole man. He still holds and swings the racket. HIS KIT IS FIXED AND MUST BE IDENTICAL IN EVERY FRAME: dirty yellow-blond hair, a RED CLOTH HEADBAND tied round his forehead, a torn red short-sleeved tennis shirt, SHORT GREY TENNIS SHORTS ENDING ABOVE THE KNEE (never long trousers), bare grey-green dead legs below them, white socks and white tennis shoes, and a wooden racket with a pale strung head. Frame 1: a SIDE SHUFFLE STEP toward the viewer — copy the legs of reference image 3, left leg driving out, the racket still held up ready. Frame 2: the same shuffle with the RIGHT leg driving out instead, identical otherwise. Frame 3: a FOREHAND SWING at the moment of contact — copy the pose of reference image 4: body rotated, the racket head out to the side at waist height. Output exactly 3 figures side by side in ONE horizontal row, all the same height. "
+  "subject": "Three frames of the ZOMBIE TENNIS PLAYER shown in the FIRST reference image — the same dead man: yellow hair, red headband, red shirt, grey shorts, grey-green corpse skin, sunken eyes, a wooden racket in his hand. The OTHER reference images are a LIVING tennis player and are there ONLY to show the POSES to copy — never the character, never the clothes, never the skin. In ALL THREE frames he is HEADLESS: his head is gone entirely and the neck is a ragged gushing stump, so this figure is A CLEAR HEAD SHORTER than a whole man. He still holds and swings the racket. HIS KIT IS FIXED AND MUST BE IDENTICAL IN EVERY FRAME: dirty yellow-blond hair, a RED CLOTH HEADBAND tied round his forehead, a torn red short-sleeved tennis shirt, SHORT GREY TENNIS SHORTS ENDING ABOVE THE KNEE (never long trousers), bare grey-green dead legs below them, white socks and white tennis shoes, and a wooden racket with a pale strung head. Frame 1: a SIDE SHUFFLE STEP toward the viewer — copy the legs of reference image 3, left leg driving out, the racket still held up ready. Frame 2: the same shuffle with the RIGHT leg driving out instead, identical otherwise. Frame 3: a FOREHAND SWING at the moment of contact — copy the pose of reference image 4: body rotated, the racket head out to the side at waist height. Output exactly 3 figures side by side in ONE horizontal row, all the same height. ",
+  "stride": [
+   [
+    0,
+    1
+   ]
+  ],
+  "palette_ref": "z_r1",
+  "palette_tol": [
+   12,
+   10,
+   6
+  ]
  },
  "racket_f_play": {
   "sprites": [
@@ -1187,7 +1217,13 @@
   "state": true,
   "check": "loose",
   "anchor": 0,
-  "subject": "Four frames of the FEMALE ZOMBIE TENNIS PLAYER shown in the FIRST reference image — the same dead woman: matted ponytail, red headband, torn red shirt, dark pleated tennis skirt, grey-green corpse skin, sunken eyes, a wooden racket in her hand. The OTHER reference images are a LIVING tennis player and are there ONLY to show the POSES to copy — never the character, never the clothes, never the skin. HER KIT IS FIXED AND MUST BE IDENTICAL IN EVERY FRAME: matted blond hair in a PONYTAIL, a RED CLOTH HEADBAND tied round her forehead, a torn red short-sleeved tennis shirt, a DARK PLEATED TENNIS SKIRT ENDING ABOVE THE KNEE, bare grey-green dead legs below it, white socks and white tennis shoes, and a wooden racket with a pale strung head. Frame 1: the READY STANCE — copy the pose of reference image 2 exactly: knees bent, weight forward on the toes, the racket held UP in front of the body in both hands, chest and face square to the viewer, waiting to return a serve. Frame 2: a SIDE SHUFFLE STEP toward the viewer — copy the legs of reference image 3, left leg driving out, the racket still held up ready in front. Frame 3: the same shuffle with the RIGHT leg driving out instead — identical to frame 2 in every other respect, only the legs swapped. Frame 4: a FOREHAND SWING at the moment of contact — copy the pose of reference image 4 exactly: the body rotated, the arm extended across, the racket head out to the side at waist height, weight on the front foot. Output exactly 4 figures side by side in ONE horizontal row, all the same height. The four figures MUST NOT TOUCH OR OVERLAP each other in any way — leave a WIDE band of empty magenta between every pair, wider than a figure, including between their rackets and their outstretched arms. "
+  "subject": "Four frames of the FEMALE ZOMBIE TENNIS PLAYER shown in the FIRST reference image — the same dead woman: matted ponytail, red headband, torn red shirt, dark pleated tennis skirt, grey-green corpse skin, sunken eyes, a wooden racket in her hand. The OTHER reference images are a LIVING tennis player and are there ONLY to show the POSES to copy — never the character, never the clothes, never the skin. HER KIT IS FIXED AND MUST BE IDENTICAL IN EVERY FRAME: matted blond hair in a PONYTAIL, a RED CLOTH HEADBAND tied round her forehead, a torn red short-sleeved tennis shirt, a DARK PLEATED TENNIS SKIRT ENDING ABOVE THE KNEE, bare grey-green dead legs below it, white socks and white tennis shoes, and a wooden racket with a pale strung head. Frame 1: the READY STANCE — copy the pose of reference image 2 exactly: knees bent, weight forward on the toes, the racket held UP in front of the body in both hands, chest and face square to the viewer, waiting to return a serve. Frame 2: a SIDE SHUFFLE STEP toward the viewer — copy the legs of reference image 3, left leg driving out, the racket still held up ready in front. Frame 3: the same shuffle with the RIGHT leg driving out instead — identical to frame 2 in every other respect, only the legs swapped. Frame 4: a FOREHAND SWING at the moment of contact — copy the pose of reference image 4 exactly: the body rotated, the arm extended across, the racket head out to the side at waist height, weight on the front foot. Output exactly 4 figures side by side in ONE horizontal row, all the same height. The four figures MUST NOT TOUCH OR OVERLAP each other in any way — leave a WIDE band of empty magenta between every pair, wider than a figure, including between their rackets and their outstretched arms. ",
+  "stride": [
+   [
+    1,
+    2
+   ]
+  ]
  },
  "racket_f_w1": {
   "sprites": [
@@ -1204,7 +1240,19 @@
   "state": true,
   "check": "same",
   "anchor": 0,
-  "subject": "Three frames of the FEMALE ZOMBIE TENNIS PLAYER shown in the FIRST reference image — the same dead woman: matted ponytail, red headband, torn red shirt, dark pleated tennis skirt, grey-green corpse skin, sunken eyes, a wooden racket in her hand. The OTHER reference images are a LIVING tennis player and are there ONLY to show the POSES to copy — never the character, never the clothes, never the skin. In ALL THREE frames her LEFT arm — the one WITHOUT the racket — IS COMPLETELY GONE. She has ONLY ONE ARM: there is no left arm, no left hand and no left sleeve anywhere in the drawing, just a ragged torn stump at the left shoulder gushing blood down her side, and her shirt is slashed open across the ribs. She still swings the racket with her remaining arm. HER KIT IS FIXED AND MUST BE IDENTICAL IN EVERY FRAME: matted blond hair in a PONYTAIL, a RED CLOTH HEADBAND tied round her forehead, a torn red short-sleeved tennis shirt, a DARK PLEATED TENNIS SKIRT ENDING ABOVE THE KNEE, bare grey-green dead legs below it, white socks and white tennis shoes, and a wooden racket with a pale strung head. Frame 1: a SIDE SHUFFLE STEP toward the viewer — copy the legs of reference image 3, left leg driving out, the racket still held up ready. Frame 2: the same shuffle with the RIGHT leg driving out instead, identical otherwise. Frame 3: a FOREHAND SWING at the moment of contact — copy the pose of reference image 4: body rotated, the racket head out to the side at waist height. Output exactly 3 figures side by side in ONE horizontal row, all the same height. "
+  "subject": "Three frames of the FEMALE ZOMBIE TENNIS PLAYER shown in the FIRST reference image — the same dead woman: matted ponytail, red headband, torn red shirt, dark pleated tennis skirt, grey-green corpse skin, sunken eyes, a wooden racket in her hand. The OTHER reference images are a LIVING tennis player and are there ONLY to show the POSES to copy — never the character, never the clothes, never the skin. In ALL THREE frames her LEFT arm — the one WITHOUT the racket — IS COMPLETELY GONE. She has ONLY ONE ARM: there is no left arm, no left hand and no left sleeve anywhere in the drawing, just a ragged torn stump at the left shoulder gushing blood down her side, and her shirt is slashed open across the ribs. She still swings the racket with her remaining arm. HER KIT IS FIXED AND MUST BE IDENTICAL IN EVERY FRAME: matted blond hair in a PONYTAIL, a RED CLOTH HEADBAND tied round her forehead, a torn red short-sleeved tennis shirt, a DARK PLEATED TENNIS SKIRT ENDING ABOVE THE KNEE, bare grey-green dead legs below it, white socks and white tennis shoes, and a wooden racket with a pale strung head. Frame 1: a SIDE SHUFFLE STEP toward the viewer — copy the legs of reference image 3, left leg driving out, the racket still held up ready. Frame 2: the same shuffle with the RIGHT leg driving out instead, identical otherwise. Frame 3: a FOREHAND SWING at the moment of contact — copy the pose of reference image 4: body rotated, the racket head out to the side at waist height. Output exactly 3 figures side by side in ONE horizontal row, all the same height. ",
+  "stride": [
+   [
+    0,
+    1
+   ]
+  ],
+  "palette_ref": "z_r1_f",
+  "palette_tol": [
+   12,
+   10,
+   6
+  ]
  },
  "racket_f_w2": {
   "sprites": [
@@ -1221,6 +1269,18 @@
   "state": true,
   "check": "same",
   "anchor": 0,
-  "subject": "Three frames of the FEMALE ZOMBIE TENNIS PLAYER shown in the FIRST reference image — the same dead woman: matted ponytail, red headband, torn red shirt, dark pleated tennis skirt, grey-green corpse skin, sunken eyes, a wooden racket in her hand. The OTHER reference images are a LIVING tennis player and are there ONLY to show the POSES to copy — never the character, never the clothes, never the skin. In ALL THREE frames she is HEADLESS: her head IS COMPLETELY GONE and SO IS HER PONYTAIL — no head, no face, no hair, no scalp and no ponytail anywhere above the shoulders, only a ragged gushing neck stump where the head was, so this figure is A CLEAR HEAD SHORTER than a whole woman. She still holds and swings the racket. HER KIT IS FIXED AND MUST BE IDENTICAL IN EVERY FRAME: matted blond hair in a PONYTAIL, a RED CLOTH HEADBAND tied round her forehead, a torn red short-sleeved tennis shirt, a DARK PLEATED TENNIS SKIRT ENDING ABOVE THE KNEE, bare grey-green dead legs below it, white socks and white tennis shoes, and a wooden racket with a pale strung head. Frame 1: a SIDE SHUFFLE STEP toward the viewer — copy the legs of reference image 3, left leg driving out, the racket still held up ready. Frame 2: the same shuffle with the RIGHT leg driving out instead, identical otherwise. Frame 3: a FOREHAND SWING at the moment of contact — copy the pose of reference image 4: body rotated, the racket head out to the side at waist height. Output exactly 3 figures side by side in ONE horizontal row, all the same height. "
+  "subject": "Three frames of the FEMALE ZOMBIE TENNIS PLAYER shown in the FIRST reference image — the same dead woman: matted ponytail, red headband, torn red shirt, dark pleated tennis skirt, grey-green corpse skin, sunken eyes, a wooden racket in her hand. The OTHER reference images are a LIVING tennis player and are there ONLY to show the POSES to copy — never the character, never the clothes, never the skin. In ALL THREE frames she is HEADLESS: her head IS COMPLETELY GONE and SO IS HER PONYTAIL — no head, no face, no hair, no scalp and no ponytail anywhere above the shoulders, only a ragged gushing neck stump where the head was, so this figure is A CLEAR HEAD SHORTER than a whole woman. She still holds and swings the racket. HER KIT IS FIXED AND MUST BE IDENTICAL IN EVERY FRAME: matted blond hair in a PONYTAIL, a RED CLOTH HEADBAND tied round her forehead, a torn red short-sleeved tennis shirt, a DARK PLEATED TENNIS SKIRT ENDING ABOVE THE KNEE, bare grey-green dead legs below it, white socks and white tennis shoes, and a wooden racket with a pale strung head. Frame 1: a SIDE SHUFFLE STEP toward the viewer — copy the legs of reference image 3, left leg driving out, the racket still held up ready. Frame 2: the same shuffle with the RIGHT leg driving out instead, identical otherwise. Frame 3: a FOREHAND SWING at the moment of contact — copy the pose of reference image 4: body rotated, the racket head out to the side at waist height. Output exactly 3 figures side by side in ONE horizontal row, all the same height. ",
+  "stride": [
+   [
+    0,
+    1
+   ]
+  ],
+  "palette_ref": "z_r1_f",
+  "palette_tol": [
+   12,
+   10,
+   6
+  ]
  }
 }