Rebuild the brute's damage, and stop generating its second frames

All four stages drawn from the healthy body in two sheets, so he keeps the same
bulk the whole way down instead of slimming as the wounds get worse — one arm and
his pole, both arms, ribs open, then headless.

The second frame of each stage is now a MIRROR of the first, not a generation.
Every attempt at drawing them moved the injury between the two feet — this is the
third fix for the same complaint — and a mirror physically cannot: the wound
stays on the same part of the body, and flipping a standing figure IS the stride
swap the B frame exists for.

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

index.html

@@ -97,6 +97,6 @@
     <p id="build"></p>
   </div>
 </div>
-<script type="module" src="main.js?v=74"></script>
+<script type="module" src="main.js?v=75"></script>
 </body>
 </html>

render.js

@@ -155,7 +155,7 @@ export function proj(x, y, z) {
 
 // ---------------------------------------------------------------- sprites ----
 // assets/<name>.png; game falls back to code-drawn figures until sprites load.
-const SPRV = 67; // asset cache-buster — bump with main.js?v=N (see the img.src note below)
+const SPRV = 68; // asset cache-buster — bump with main.js?v=N (see the img.src note below)
 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_swing1','p_swing2','p_die1','p_die2','p_die3','p_die4','p_die5',
                  'o_idle1','o_idle2','o_bounce','o_bounce2','o_toss','o_smash','o_run1','o_run2','o_swing1','o_swing2',