fix(supabase): add esm wrapper to resolve module not found error in nuxt

[7ttp]

Fixes #1880

Problem

ESM imports fail with ERR_MODULE_NOT_FOUND in Nuxt 3 and other strict ESM environments because the dist/module build has imports without .js extensions.

Solution

Add an ESM wrapper that re-exports from the CommonJS build, following the same pattern used by postgrest-js.

Changes

• Add exports field to package.json for proper ESM/CJS resolution
• Add wrapper.mjs that re-exports all exports from the CJS build
• Add scripts/copy-wrapper.cjs to copy wrapper during build
• Update module field to point to the wrapper

Tested

• ESM import works via wrapper
• CJS import still works
• Direct imports to dist/module/* still work (for Deno tests)

cc @mandarini

[coveralls]

coverage: 95.367% (+14.2%) from 81.173%
when pulling 8fc97e4 on 7ttp:Nuxt1
into 8769da9 on supabase:master.