refactor: replace overloaded surface terminology

packages/host/apiproxy/src/api/index.ts

@@ -19,7 +19,7 @@ import type { LlmApi } from './llm.ts'
 import type { DownloadsApi } from './downloads.ts'
 import type { ClientResponse, RpcReceipt } from './rpc.ts'
 
-/** Root interface of the unified API surface. New client-request domain = one new file pair + one field here + one map row. */
+/** Root interface of the unified API. New client-request domain = one new file pair + one field here + one map row. */
 export interface ApiProxy {
   sessions: SessionsApi
   subagents: SubagentsApi

packages/host/apiproxy/src/api/rpc.ts

@@ -116,7 +116,7 @@ export type RpcResult<T> = { ok: true; value: T } | { ok: false; error: RpcError
 
 /**
  * Fold a transport exception into the RpcResult error branch (unified error
- * surface; 'internal' as the catch-all code). Lives with RpcResult so every
+ * API; 'internal' as the catch-all code). Lives with RpcResult so every
  * carrier consumer folds the same way.
  * @param error - the thrown value from the carrier.
  * @returns the error branch of an RpcResult.

packages/host/apiproxy/src/api/sessions.schema.ts

@@ -1,7 +1,7 @@
 /**
  * sessions domain zod schemas (names derived from map keys: sessionListRequestSchema /
  * sessionListValueSchema). SessionEvent passthrough = strict envelope (type/seq/time) + wide
- * data: the merge-extensible event surface keeps an unknown-type branch at the union level,
+ * data: the merge-extensible event API keeps an unknown-type branch at the union level,
  * with no field-level passthrough. SessionId brand cast point: sessionIdSchema, and only there.
  */