Add pressure dial, wave spawn telegraphs, and readability pass

- Bigger gore-red Minis (r10->14, sprite 32->48) with regenerated art
- Wider, walkable doorways: clear passage for open, teeth only when locked
- 500ms spawn telegraph so wave spawns no longer blindside the player
- Item stickiness ramps 10%/owned item (cap 50%) instead of flat 50%
- Title-screen Pressure Dial (-5..+5) tunes rise/relief; score x live pressure
- Vitals HUD: two-row hearts, half-container outlines, half-heart shield pips
- Readable 8-page field manual (bigger panel + fonts, implants split)
- HUD opacity slider in pause menu (boss bar + toasts stay opaque)
- Scrap Feed now has diminishing returns like Thick Hide
- Docs, cache-bust v37, and smoke coverage for all of the above

js/player.js

@@ -177,7 +177,7 @@ function pressureRelief(dmgTaken) {
   const severity = clamp(dmgTaken / Math.max(2, p.stats.maxHp * 0.25), 0.4, 2);
   const desperation = 1 + (1 - hpFrac) * 2;
   const churn = 1 + Math.min(G.recentHits.length, 4) * 0.35;
-  return 0.03 * severity * desperation * churn;
+  return PRESSURE_DROP_BASE * PRESSURE_UNIT * severity * desperation * churn * pressureDropScale();
 }
 
 function hurtPlayer(dmg, ang, attacker) {