fix(expo): preserve config plugin resolution in packed builds

[RobJacobson]

Description

Addresses config-plugin discovery failures reported in #4147 and #4286.

Bob’s generated lib/module/package.json causes the legacy Expo resolver to search for app.plugin.js inside that directory. It misses the root plugin and loads the React Native runtime entry, which fails in Node.

Disable Bob’s strict ESM packaging metadata while retaining module output and Metro’s native/web selection. Add regression coverage against freshly built npm archives using both legacy and current Expo resolvers, plus Metro resolution for compiled and source entries.

Also exclude generated lib/ output from the general source type check. Copied native specs were resolving type imports against adjacent JavaScript with erased types.

Depends on #4346. This branch currently includes its type-export commit, which the packed declaration-consumer checks build on.

Reproduction and regression results

Run yarn jest __tests__/packageResolution.test.js --runInBand.

Check	Before	After
Packed-package resolution suite	1 failed, 8 passed	9 passed
Legacy Expo plugin discovery	ERR_MODULE_NOT_FOUND for lib/module/Mapbox	Loads root app.plugin.js; registers Android/iOS mods
Metro iOS, Android and web resolution	All 6 cases passed	All 6 cases passed
General type check after building	51 errors in generated lib/ files	No errors

Current Expo plugin discovery and the explicit app.plugin.js export pass before and after.

Validation

• yarn build — passed.
• yarn type:check after the fresh build — passed.
• yarn test — lint passed with warnings; 27 suites and 182 tests passed, including packed declaration-consumer checks.
• git diff --check — passed.

Native and web verification covers module resolution. Device runtime behavior was not exercised; #4286’s separate “module undefined” report remains unconfirmed.

Checklist

• Read CONTRIBUTING.md and .github/REPRODUCING.md.
• Reproduced the packaging failure before fixing it.
• Verified the same reproducer after the fix.
• Code generation: not applicable; no component or style changes.

[mfazekas]

Thanks for digging into the resolver mechanism. The failure comes from Expo Tools still pinning @expo/config-plugins 4.1.5 (the current Expo CLI resolves our app.plugin.js fine), so I think the fix belongs in Expo Tools. I don't see much benefit in turning off bob's esm output, which is the create-react-native-library default, just to accommodate an outdated tool. Also, this branch carries #4346's type-export changes; those should stay in that PR.

[mfazekas]

Closing this, sorry. We'd rather keep bob's esm output and see the plugin resolution fixed in Expo Tools. Thanks again for tracking down the mechanism.