Share package.json cache and skip collecting failed lookup locations in auto-imports

[andrewbranch]

#2780 shows a lot of allocations going to package.json parsing. I can't repro myself, but based on the profile and the report that the problem started after #2502, I think this is probably it. The failed lookup locations are also not used by auto-imports, so that should be an additional small win. I tried invoking completions in a file in Signal-Desktop as a random benchmark, and this brought total allocs down from 0.78 GB to 0.75 GB. Not huge, but maybe there's a pathological case I haven't been able to repro. Worth a try!

[Copilot]

Pull request overview

This PR targets reducing memory allocations in the auto-import pipeline by reusing a shared package.json parse cache across resolver instances and by skipping collection of lookup-location metadata that auto-imports don’t consume. This fits into the TypeScript-Go language server’s performance work, particularly around module resolution during completion/auto-import indexing.

Changes:

• Add module.ResolverOptions + NewResolverWithOptions to allow sharing a packagejson.InfoCache and disabling lookup-location collection.
• Gate recording of failedLookupLocations/affectingLocations behind a resolver option to avoid unnecessary allocations.
• Update auto-import registry building to create one shared package.json cache and pass it into all module resolvers used during extraction/indexing.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
internal/module/resolver.go	Adds resolver options, shared package.json cache support, and conditional lookup-location recording.
internal/ls/autoimport/util.go	Threads resolver options through the auto-import module resolver helper.
internal/ls/autoimport/registry.go	Creates and reuses a shared package.json cache for auto-import indexing resolvers; enables skipping lookup locations.