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

docs/README.md

@@ -66,4 +66,4 @@ Runs the smoke test (`test/smoke.js`).
 
 ## The fantasy in one paragraph
 
-Rooms lock behind you. The meat waves come in threes. Elites gleam gold and drop the good stuff. The Pressure gauge climbs the longer you stay flawless, and every boss — saw, crown, mother, flenser, choir, father, auger, scald — cycles back around, deeper and meaner, until the meat finally wins. Take the meat. Take the stairs.
+Rooms lock behind you. The meat waves come in threes. Elites gleam gold and drop the good stuff. Set the Pressure Dial before you descend — the gauge climbs the longer you stay flawless, and every point of score rides it. Every boss — saw, crown, mother, flenser, choir, father, auger, scald — cycles back around, deeper and meaner, until the meat finally wins. Take the meat. Take the stairs.