fix: add .npmrc shamefully-hoist for native module compilation

pnpm's isolated store prevents native post-install scripts from finding
their dependency binaries (node-pre-gyp, prebuild-install). This causes
@discordjs/opus and @lng2004/node-datachannel to fail during pnpm install.

Enabling shamefully-hoist flattens node_modules so native scripts can
resolve their dependencies correctly.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.npmrc

@@ -0,0 +1 @@
+shamefully-hoist=true