The 0.90.0 .npmignore never took effect — npm uses the files array as the
allowlist and bypasses .npmignore for included dirs, so stray
examples/**/*.gba + .build.log still packed (only masked earlier by manually
deleting the stray before packing). Moved the exclusions into files[] itself
(!examples/**/*.gba, etc.), where npm honors negations. Verified: a stray .gba
+ build log no longer appear in npm pack; .p8 example carts + input assets
still ship. Also removed a stray examples/hwtest/ build-output dir.