API: make object registries project-specific to avoid id collisions on types and signatures

[piotrtomiak]

It will also make it easier to refactor checker method into Type/Symbol/Signature classes.

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

This PR adds API support for extracting the true/false branches of conditional types, and fixes cross-project handle collisions by scoping type/symbol/signature registries per project within a snapshot.

Changes:

• Introduced getTrueTypeOfConditionalType / getFalseTypeOfConditionalType methods end-to-end (checker exports, API proto, session handlers, TS clients, tests).
• Replaced snapshot-global registries with per-project registries to prevent ID collisions when multiple projects are open in the same snapshot.
• Updated sub-property endpoint params to include project so the server can resolve handles in the correct project registry.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
internal/checker/exports.go	Exposes conditional-type true/false branch getters on Checker.
internal/api/session.go	Scopes registries per project; threads projectID through registration/handle-resolution and adds new API handlers.
internal/api/proto.go	Adds new method names + unmarshalers; adds project to sub-property param types.
_packages/native-preview/src/api/sync/api.ts	Moves object registries from snapshot-level to project-level; adds conditional-type branch methods.
_packages/native-preview/src/api/async/api.ts	Async equivalent of sync client changes (project-level registries + new methods).
_packages/native-preview/test/sync/api.test.ts	Adds tests for conditional-type branch getters and multi-project type ID collision regression.
_packages/native-preview/test/async/api.test.ts	Async equivalent tests for new methods and multi-project collision regression.