Generate the API reference; export the types public signatures name

[kkdev92]

Summary

npm run docs:api renders every public entry point (., ./testing, ./testing/vitest, ./testing/vitest-config, ./testing/mock, ./vscode, ./std, ./ui) with TypeDoc, and CI runs it with warnings as errors.

Setting that up found what the warnings exist to find: types that public signatures name but the package never exported. A consumer who got a TreeItemLike back from a tree source, a StatusBarItemHandle from a fake, a SettingBaseOptions from setting.boolean, or a CancellationReason off an OperationCancelledError could hold the value and not be able to write its type. They are exported now — type-only, from the entry whose signatures name them. CancellationReason and OperationKind are exported as values too, since they are compared against.

ApplicationPlan and ModuleDefinition are handled differently: their members are marked @internal. Both are handles — defineExtension and createTestHost consume them — and describePlan is the readable form. Exporting fifteen registration record types would have widened the public surface without giving a consumer anything describePlan does not.

What changed

• typedoc.json, npm run docs:api, a CI step after knip, and docs/api/ in .gitignore. npm run quality includes the step.
• Root exports: the port vocabulary public signatures use (TreeItemLike, PlatformRegistration, ProgressReporterLike, QuickPickItemLike, QuickInputButtonLike, TreeDataSource, TreeDragAndDrop, MarkdownLike, TooltipLike, LanguageSelectorLike, LanguageFilterLike, CommandLike, CommandLinkLike, AccessibilityInformationLike, RelativePatternLike, NotificationSeverity, ProgressArea, QuickInputCapability), plus DisposableLike, SubscriptionsHost, WebviewLike, WebviewCspSourceLike, DefineExtensionOptionsWithExports, StandardSchemaResult, SettingBaseOptions (previously the unexported BaseOptions), CommandDescriptor, SchemaPathSegment, RememberedChoice, Emitter, StatusBarItemDefinition, LanguageStatusItemDefinition, CancellationReason, OperationKind.
• ./testing exports: the port types the fakes implement or hand back (CancellationTokenLike, FileWatcherHandle, InputBoxLike, QuickPickLike, LanguageStatusItemHandle, LanguageStatusItemFields, StatusBarItemHandle, StatusBarItemFields, NotificationActionLike, LocalizedMessage, SettingsChangeSource, ActiveTextEditor, WebviewPanelSurface, WebviewViewSurface) and the host types TestHost exposes (Application, ApplicationHost, ExtensionHostContext, HostInspection, HostState, StopReason).
• {@link} tags that pointed at internal symbols became plain code.

No runtime behaviour changes. The API reference is generated, not hosted yet; publishing it is a separate step.

Verification

• npm run quality (now including docs:api): 1074 tests, 0 TypeDoc warnings with treatWarningsAsErrors.
• npm run verify:package: the tarball installs and type-checks from a consumer; the CLI runs from the installed package.
• A real extension built on this package installed the tarball with no source changes: typecheck, lint, 236 unit and 35 integration tests pass.

🤖 Generated with Claude Code