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/client/connection/tests/websocket-downlink.spec.ts

@@ -93,7 +93,7 @@ describe('WebSocket downlinks', () => {
       },
       async function * (signal) {
         try {
-          yield { rpcId: RpcId('host-1'), payload: { type: 'host/commands-changed' } }
+          yield { rpcId: RpcId('host-1'), payload: { type: 'host/remote-event', event: 'commands/change', args: [] } }
           await untilAbort(signal)
         } finally {
           hostAborted = true
@@ -116,8 +116,8 @@ describe('WebSocket downlinks', () => {
     expect(await hostFrame).toEqual({
       type: 'server-request',
       rpcId: 'host-1',
-      method: 'host/commands-changed',
-      payload: { type: 'host/commands-changed' },
+      method: 'host/remote-event',
+      payload: { type: 'host/remote-event', event: 'commands/change', args: [] },
     })
 
     const muxClosed = once(mux, 'close')