JavaScript port decodes YAPF 2; VS Code and Figma open every file

yapf.js: decodeTexture (container, yapf-sum checks, code books with
context decoding, 16-bit / float planes, GPU block tiles), BC1-BC7 /
BC6H block decoding and textureToRGBA for display. Matches the C library
on 417 generated files (surfaces bit-exact) and survives fuzzing with
clean YapfErrors; fixtures in bindings/js/test-data keep it checked.

VS Code preview: pickers for mip, face, layer, frame and slice; storage,
normal-map convention and version in the info bar. Figma import:
textures converted to 8-bit, 8-bit images stay exact.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DVrVthWN8GsmgHGUhhsCYm

bindings/js/test-data/v2-expected.json

@@ -0,0 +1,137 @@
+{
+ "v2-rgba8.yapf": {
+  "surfaces": [
+   480599072
+  ],
+  "preview0": 480599072
+ },
+ "v2-float-gray-entropy.yapf": {
+  "surfaces": [
+   1656156314
+  ],
+  "preview0": 2474033295
+ },
+ "v2-half-gray-alpha-entropy.yapf": {
+  "surfaces": [
+   2599040047
+  ],
+  "preview0": 297007736
+ },
+ "v2-rgba8-entropy.yapf": {
+  "surfaces": [
+   554695116
+  ],
+  "preview0": 554695116
+ },
+ "v2-u16-rgba-entropy.yapf": {
+  "surfaces": [
+   3416063949
+  ],
+  "preview0": 1518500476
+ },
+ "v2-cube-mips.yapf": {
+  "surfaces": [
+   3098789294,
+   2090642189,
+   3178169037,
+   3641419477,
+   333399741,
+   2333110333,
+   1703812753,
+   3098789294,
+   2090642189,
+   3178169037,
+   3641419477,
+   333399741,
+   2333110333,
+   1703812753,
+   3098789294,
+   2090642189,
+   3178169037,
+   3641419477,
+   333399741,
+   2333110333,
+   1703812753,
+   3098789294,
+   2090642189,
+   3178169037,
+   3641419477,
+   333399741,
+   2333110333,
+   1703812753,
+   3098789294,
+   2090642189,
+   3178169037,
+   3641419477,
+   333399741,
+   2333110333,
+   1703812753,
+   3098789294,
+   2090642189,
+   3178169037,
+   3641419477,
+   333399741,
+   2333110333,
+   1703812753
+  ],
+  "preview0": 3098789294
+ },
+ "v2-u16-volume.yapf": {
+  "surfaces": [
+   1504297975,
+   2857113671,
+   3272367306,
+   4248642449
+  ],
+  "preview0": 3611091147
+ },
+ "v2-animation-notes.yapf": {
+  "surfaces": [
+   2496952478,
+   2084186354,
+   2971951804,
+   4204487618
+  ],
+  "preview0": 2496952478
+ },
+ "v2-bc6h-random-blocks.yapf": {
+  "surfaces": [
+   2051803746,
+   562394057,
+   2093502260
+  ],
+  "preview0": 2386146506
+ },
+ "v2-bc7-random-blocks.yapf": {
+  "surfaces": [
+   3714498223,
+   242396130,
+   2835116443
+  ],
+  "preview0": 4042788133
+ },
+ "v2-bc3-packed.yapf": {
+  "surfaces": [
+   1798067479
+  ],
+  "preview0": 3027945807
+ },
+ "v2-bc5-packed.yapf": {
+  "surfaces": [
+   1681957115
+  ],
+  "preview0": 1079658926
+ },
+ "v2-bc7-encoded.yapf": {
+  "surfaces": [
+   3415378546
+  ],
+  "preview0": 851871445
+ },
+ "v2-bc6h-encoded.yapf": {
+  "surfaces": [
+   3372163902
+  ],
+  "preview0": 89762387
+ }
+}