feat(remote): deliver allowlisted Host events through ctx.remote.$on

api/remotes owns the allowlist and its type projection; type-meta owns the shape
predicate, the selection seat, and the internal remote/host-event carrier
signal; api/gateway's Client half turns that signal into $on callbacks through a
private dispatch. apiproxy forwards each allowlisted emission verbatim in one
host/remote-event frame, registered ahead of the derived invalidation frames so
frame order is unchanged, and drops the three per-event variants it replaces.
Owner packages move their Events declarations into client-safe ./types exports,
so a consumer's listener signature is the Host's own declaration.

packages/api/remotes/src/index.ts

@@ -1,5 +1,16 @@
 /** Host BFF entry and Loader shell for the Remote contribution assembly. */
 
+// import type { TypeRTForwardableEvent } from '@deepseek-ai/dsh-type-meta'
+// import { API_REMOTE_FORWARDED_EVENTS } from './types.ts'
+
+// // The owner packages' client-safe `./types` exports carry the cordis `Events`
+// // declarations for every allowlisted event. Pulling them into this face is what
+// // makes the shape assertion below judge real signatures rather than an empty
+// // event vocabulary.
+// import type {} from '@deepseek-ai/dsh-commands/types'
+// import type {} from '@deepseek-ai/dsh-credentials/types'
+// import type {} from '@deepseek-ai/dsh-settings/types'
+
 export {
   ApiRemoteSessionNotFound,
   ApiRemoteSubagentSessionOwnership,
@@ -13,6 +24,18 @@ export type {
   ApiRemoteAgentResult,
   ApiRemoteLookupError,
 } from './agent-lookup.ts'
+export { API_REMOTE_FORWARDED_EVENTS } from './types.ts'
+export type { ApiRemoteForwardedEvent } from './types.ts'
+
+// Shape gate over the allowlist, kept in the Host face because the Host's event
+// vocabulary is the authoritative one. It pins three things at compile time:
+// every entry NAMES a declared event (the predicate is keyed on `keyof
+// Events`), no entry BINDS a Scope (a scoped event's `ThisParameterType` is not
+// `unknown`, which is how "must not depend on AgentScope" is stated statically),
+// and every entry is ONE-WAY (a waterfall or bail shape returns something other
+// than void and is excluded). Widening the array to an event that fails any of
+// these fails here, not on the wire.
+// API_REMOTE_FORWARDED_EVENTS satisfies readonly TypeRTForwardableEvent[]
 
 /** Host plugin body; the selected contributions mount only in Client environments. */
 export function apply(): void {}