Collapse dusk.dsk from two zip archives into one, all uncompressed

Bulk assets (mp3, png) are already compressed at the file level, so a
DEFLATE pass on top bought negligible space for real CPU cost. Packs
everything into a single ZIP_STORED archive instead, so every entry
(not just locale/*) gets the reliable repeated seeking/re-opening that
libzip only supports for uncompressed entries. Header shrinks from 32
to 16 bytes; version bumped to 2 so a stale pre-change dusk.dsk is
rejected and rebuilt rather than misread.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

src/duskvita/asset/assetvita.c

@@ -10,9 +10,7 @@
 #include "assert/assert.h"
 
 errorret_t assetInitVita(void) {
-  errorChain(
-    assetDskOpenFromPath(ASSET_VITA_DSK_PATH, &ASSET.zip, &ASSET.zipStored)
-  );
+  errorChain(assetDskOpenFromPath(ASSET_VITA_DSK_PATH, &ASSET.zip));
   errorOk();
 }