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/sfxbank.js

@@ -115,7 +115,7 @@ const SfxBank = {
     if (this.buffers.has(name) || this.pending.has(name) || this.failed.has(name)) return;
     const file = this.FILES[name];
     if (!file || !this.ctx || typeof fetch !== 'function') return;
-    const job = fetch('/assets/sfx/' + encodeURIComponent(file) + '?v=36')
+    const job = fetch('/assets/sfx/' + encodeURIComponent(file) + '?v=37')
       .then(r => { if (!r.ok) throw new Error('HTTP ' + r.status); return r.arrayBuffer(); })
       .then(bytes => this.ctx.decodeAudioData(bytes))
       .then(buffer => this.buffers.set(name, this.trim(buffer)))