Add Remote Braille IPC to the host and both SDKs

remote.braille requests and events carry a typed op under a
braille-stream lease: the controller's width and gestures for a
controlled reader, rendered cells back to its child, and cells, local
geometry and display gestures for a controller. Direction is validated
per role; a full mailbox revokes the lease. No display owner is
attached yet.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/tentacle/remote.go

@@ -191,6 +191,16 @@ func (session *Session) revoke_remote_locked(reason string, notify bool) {
 			}
 		}
 	}
+	if session.remoteBraille != nil {
+	drainBraille:
+		for {
+			select {
+			case <-session.remoteBraille:
+			default:
+				break drainBraille
+			}
+		}
+	}
 	if session.remoteCapture != nil {
 	drainCapture:
 		for {
@@ -292,6 +302,8 @@ func (session *Session) remote_call_locked(method string, params json.RawMessage
 		return session.remote_key_locked(params)
 	case "remote.focus":
 		return session.remote_focus_locked(params)
+	case "remote.braille":
+		return session.remote_braille_locked(params)
 	case "remote.open":
 		var request tentaclewire.RemoteOpen
 		if decode_strict(params, &request) != nil || len(request.Action) != 32 || request.Epoch == 0 || !tentaclewire.ValidRoleGrants(request.Role, request.Grants) {