fix(spec): keep ObjectOSKernel as an interface extension; commit api-surface snapshot

The api-surface guard flagged interface→type as a removal (breaking).
ObjectOSKernel is now '/** @deprecated */ interface ObjectOSKernel
extends IKernel {}' — declaration merging and interface identity are
preserved, so the surface records additions only:
+ KernelCapabilitiesSchema (const), + KernelCapabilities (type),
+ IKernel (interface). check:api-surface green after a full dist build.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0162o68e5w3bpUBEVRQboUGG

Author: claude

packages/spec/api-surface.json

@@ -44,6 +44,8 @@
     "ExpressionSchema (const)",
     "F (const)",
     "GUEST_POSITION (const)",
+    "KernelCapabilities (type)",
+    "KernelCapabilitiesSchema (const)",
     "MAP_SUPPORTED_FIELDS (const)",
     "METADATA_ALIASES (const)",
     "MIGRATIONS_BY_MAJOR (const)",
@@ -799,6 +801,7 @@
     "HttpServerConfig (type)",
     "HttpServerConfigInput (type)",
     "HttpServerConfigSchema (const)",
+    "IKernel (interface)",
     "ISettingsCapability (interface)",
     "ISettingsClient (interface)",
     "InAppNotification (type)",

packages/spec/src/system/types/plugin.ts

@@ -69,8 +69,9 @@ export interface IKernel {
   on(event: string, handler: (data: any) => void): () => void;
 }
 
-/** @deprecated Renamed — use {@link IKernel}. The "ObjectOS" layer name is retired; ObjectOS now names the commercial runtime environment. */
-export type ObjectOSKernel = IKernel;
+/** @deprecated Renamed — use {@link IKernel}. The "ObjectOS" layer name is retired; ObjectOS now names the commercial runtime environment. Kept as an empty interface extension (not a type alias) so declaration merging and the published API surface stay interface-compatible. */
+// eslint-disable-next-line @typescript-eslint/no-empty-object-type
+export interface ObjectOSKernel extends IKernel {}
 
 /**
  * Plugin Context provided to plugin lifecycle methods.