Seedbox v0.1 + firmware, generic kit/synth, ROOT/SCALE pages

First commit of the repo. Contents beyond the v0.1 simulator and layout:

- Full Pico 2 W firmware (firmware/app, drivers, engine port, host test).
- BANK page and 404 mode A/B removed; learned pads play exactly what was learned.
- 404/MiniFreak renamed to KIT/SYNTH throughout (jacks, code, sim, docs,
  layout labels; wiring rebuilt).
- ROLL returns to page select after a re-roll; a freshly learned track turns on.
- LCD contrast 66.
- ROOT and SCALE pages: 21 scales, AUTO = the seed picks; global and sticky.

Intended music change: the scale table grew from 8 to 21 and AUTO picks from
all of them, so every seed's scale changed. Vectors regenerated with
npm run vectors, plus new key-override cases. Flash record is now version 2.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

test/cases.js

@@ -0,0 +1,22 @@
+/* The golden-vector case list. Shared by gen-vectors.js and check-vectors.js. */
+var SEEDS=[0x5EEDB0C5,0x00000001,0xDEADBEEF,0x12345678,0xC0FFEE00,0x0BADF00D];
+var SETS=[[64,32],[0,0],[127,0],[127,127],[100,90],[40,64]];   // [energy, drift]
+var BARS=8;
+function cases(){
+  var out=[];
+  SEEDS.forEach(function(seed){ for(var gen=0;gen<5;gen++) SETS.forEach(function(ed){
+    out.push({seed:seed,salts:[0,0],gen:gen,energy:ed[0],drift:ed[1],fillBars:[],scale:-1,root:-1});
+  }); });
+  // salts (re-rolling one half of the seed) and FILL
+  [0,2,4].forEach(function(gen){
+    out.push({seed:0x5EEDB0C5,salts:[3,0],gen:gen,energy:64,drift:32,fillBars:[],scale:-1,root:-1});
+    out.push({seed:0x5EEDB0C5,salts:[0,5],gen:gen,energy:64,drift:32,fillBars:[],scale:-1,root:-1});
+    out.push({seed:0x5EEDB0C5,salts:[0,0],gen:gen,energy:80,drift:50,fillBars:[3,7],scale:-1,root:-1});
+  });
+  // ROOT / SCALE pages: [seed, gen, scale, root]; -1 = AUTO. Covers 5-, 6-, 7- and 8-note scales and each override alone.
+  [[0x5EEDB0C5,0,14,2],[0x5EEDB0C5,2,19,9],[0x5EEDB0C5,4,0,7],[0xDEADBEEF,1,18,-1],[0x12345678,3,-1,5],[0xC0FFEE00,0,7,11],[0x00000001,1,20,0]].forEach(function(k){
+    out.push({seed:k[0],salts:[0,0],gen:k[1],energy:64,drift:32,fillBars:[3],scale:k[2],root:k[3]});
+  });
+  return out;
+}
+module.exports={cases:cases,BARS:BARS};