Two frames each: the run cycles land where the zombies always were

The live bench session's verdict, in Oliver's words: "this looks better than
anything before." Six and eight real phases at speed read as flicker on a
far-court body — the zombies never had this problem because their walks are
FOUR well-chosen frames at a calm rate, and the fix was to stop out-drawing
them. Each opponent now runs a TWO-frame true leg-swap pair — his frames 1+2
of the grid roll, hers 7+8 of the face-transplant cycle, both picked live on
the bench with SPR swaps — at TUNE.runHz2 = 1.7 (the old hardcoded 4.5 for
short cycles was most of a stride per display frame; that is the strobe).

The tuning rig ships too: TUNE.runN (frame-count override, 0 = probe),
T.SPR for live frame swaps, and the bench's living slots — the next cadence
question gets answered by watching, not rolling. Twelve run sprites become
four; the SPR list says why. SPRV 124, main.js v248.

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

src/render.js

@@ -221,16 +221,16 @@ function farB(z) {
 // Asset cache-buster — bump with main.js?v=N (see the img.src note below). EXPORTED because the
 // menu screens hang <img> tags on the same files, and two copies of this number is one copy too
 // many: the one that does not get bumped is the one that serves a cached 404.
-export const SPRV = 123;
+export const SPRV = 124;
 // The boot bar in main.js watches this. Nothing here CHANGES when things load — every sprite was
 // already requested at import — it just makes the wait visible and holds the menu back until the
 // last sheet has landed. See the onerror note below for the other half of "sometimes missing".
 export const LOAD = { done: 0, total: 0 };
-const SPR = {};
+export const SPR = {};
 for (const n of ['p_idle1','p_idle2','p_bounce','p_bounce2','p_toss','p_smash','p_run1','p_run2','p_run3','p_run4','p_run5','p_run6','p_swing1','p_swing2','p_die1','p_die2','p_die3','p_die4','p_die5',
                  'p_pull', // the serve wind-up: the racket dropping behind him while the pull is drawn
                  'o_idle1','o_idle2','o_bounce','o_bounce2','o_toss','o_smash','o_swing1','o_swing2',
-                 'o_run1','o_run2','o_run3','o_run4','o_run5','o_run6', // the rolled 6-frame cycle (a 2x6 grid roll is TWO cycles — one row IS the cycle, never stitch the halves)
+                 'o_run1','o_run2', // TWO frames, a true leg-swap pair — the whole 2026-08-14 tuning session's verdict: fewer, better-chosen frames at a calm rate beat every 6/8-frame roll ('this looks better than anything before')
                  'x_ump','x_boyrun1','x_boyrun2','x_boyrun3','x_boyrun4',
                  'x_crowd','x_crowd2','x_ads',                 // CENTRE COURT (grass) — also the fallback set
                  'x_crowd_c','x_crowd_c2','x_ads_c',           // TERRE ROUGE (clay)
@@ -290,7 +290,7 @@ for (const n of ['p_idle1','p_idle2','p_bounce','p_bounce2','p_toss','p_smash','
                  // could actually see was blue popping in after three frames of white.
                  'p_die1_f','p_die2_f','p_die3_f','p_die4_f','p_die5_f',
                  'o_idle1_f','o_idle2_f','o_bounce_f','o_bounce2_f','o_toss_f','o_smash_f',
-                 'o_run1_f','o_run2_f','o_run3_f','o_run4_f','o_run5_f','o_run6_f','o_run7_f','o_run8_f','o_swing1_f','o_swing2_f',
+                 'o_run1_f','o_run2_f','o_swing1_f','o_swing2_f', // her pair likewise (frames 7+8 of the face-transplant cycle)
                  'z_c1_f','z_c2_f','z_c3_f','z_c4_f','z_cw1_f','z_cw2_f','z_cw1b_f','z_cw2b_f',
                  'z_r1_f','z_r2_f','z_r3_f','z_r4_f',
                  'z_rw1_f','z_rw1b_f','z_rw1s_f','z_rw2_f','z_rw2b_f','z_rw2s_f',
@@ -1488,11 +1488,12 @@ function drawChar(ch) {
   // The run cycle at whatever count the character's sheet carries: the _runroll.py cycles are 6
   // (one call, one row, one character — see assets/_runroll.py for why the old per-frame art
   // flickered); un-rolled characters fall back to 4 or 2.
-  const runN = SPR[pre + 'run8'] ? 8 : SPR[pre + 'run6'] ? 6 : SPR[pre + 'run4'] ? 4 : 2;
+  // TUNE.runN: live override for the bench's tuning sessions (0 = probe the sheet as always)
+  const runN = TUNE.runN || (SPR[pre + 'run8'] ? 8 : SPR[pre + 'run6'] ? 6 : SPR[pre + 'run4'] ? 4 : 2);
   // The rolled 6/8-frame cycles run at their own STRIDE RATE (TUNE.runHz, cycles/s). The old 4.5
   // was tuned on 2-4 near-duplicate frames, where it read as vigour — on eight real phases it was
   // a strobe ("very flashy and unnatural"), most of a full stride every display frame.
-  if (ch.pose === 'run') name = pre + 'run' + (Math.floor(ch.runT * (runN >= 6 ? TUNE.runHz : 4.5) * runN) % runN + 1);
+  if (ch.pose === 'run') name = pre + 'run' + (Math.floor(ch.runT * (runN >= 6 ? TUNE.runHz : TUNE.runHz2) * runN) % runN + 1);
   // (the receiver used to flip to run1/run2 here as a "split-step" — it read as a man sprinting on
   //  the spot, because the run frames are a full leaning stride, not a ready-hop. He idles now.)
   if (ch.pose === 'swing') name = pre + (ch.poseT < 0.15 ? 'swing1' : 'swing2');