Duplicate @tanstack/query-core causes type errors with Bun package manager

[piotrkulpinski]

Description

When using @tanstack/react-query@5.96.2 alongside packages that depend on @tanstack/query-core (e.g. @orpc/tanstack-query), Bun creates a nested duplicate of @tanstack/query-core inside node_modules/@tanstack/react-query/node_modules/, even when the versions are identical (both 5.96.2).

This causes TypeScript type errors because the two copies produce incompatible types (different QueryClient class instances from different module paths):

Type 'MutationObserverOptions<...>' is not assignable to type 'UseMutationOptions<...>'.
  Types of property 'onError' are incompatible.
    ...
    Property '#private' in type 'QueryClient' refers to a different member
    that cannot be accessed from within type 'QueryClient'.

Reproduction

1. Create a project with Bun as the package manager
2. Install @tanstack/react-query@^5.96.2 and any package that depends on @tanstack/query-core (e.g. @orpc/tanstack-query)
3. Run bun install
4. Observe node_modules/@tanstack/react-query/node_modules/@tanstack/query-core/ exists as a separate copy
5. TypeScript reports type incompatibilities between the two QueryClient classes

Expected behavior

@tanstack/query-core should be hoisted to a single copy in node_modules/@tanstack/query-core/, even when multiple packages depend on it.

Environment

• Bun: 1.3.9+
• @tanstack/react-query: 5.96.2
• @tanstack/query-core: 5.96.2 (duplicated)
• TypeScript: 6.0.2

Workaround

Adding @tanstack/query-core as a direct dependency or using "overrides" in package.json forces deduplication.