backward compat: rename so that "undefined" means it is like before the two flags were introduced.

Author: hpk42

src-docs/spec/CHANGELOG.md

@@ -4,7 +4,7 @@
 
 ### New APIs
 
-- add `webxdc.appSenderAddr` and `webxdc.canSendUpdatesToAllPeers` 
+- add `webxdc.appSenderAddr` and `webxdc.canOnlySendUpdatesToAppSender` 
   to allow apps to determine their role and their ability to send updates.
 ## [1.3] - 2026-02-11
 

src-docs/spec/messenger.md

@@ -54,7 +54,7 @@ When starting a web view for a webxdc app to run, messenger implementors
 
 - MUST support `<meta name="viewport" ...>` is useful especially as webviews from different platforms have different defaults
 
-- MUST support `window.webxdc.appSenderAddr` and `window.webxdc.canSendUpdatesToAllPeers`
+- MUST support `window.webxdc.appSenderAddr` and `window.webxdc.canOnlySendUpdatesToAppSender`
   to allow apps to determine their role and their ability to send updates.
 
 - MUST support `<input type="file">` to allow importing of files;

src-docs/spec/selfAddr_and_selfName.md

@@ -45,21 +45,22 @@ This supports a common development model where a "central" app instance
 (the sender's) processes all updates and distributes the resulting state
 back to all peers.
 
-## canSendUpdatesToAllPeers
+## canOnlySendUpdatesToAppSender
 
 ```js
-window.webxdc.canSendUpdatesToAllPeers
+window.webxdc.canOnlySendUpdatesToAppSender
 ```
 
-`canSendUpdatesToAllPeers` is a boolean that is `true` if the local user
-can send [updates](./sendUpdate.md) to everyone in the chat.
-If it is `false`, updates sent by the local user will only be seen by the app sender.
+`canOnlySendUpdatesToAppSender` is a boolean that is `true` if updates sent
+by the local user will only be seen by the app sender.
+If it is `false` or `undefined`, the local user can send [updates](./sendUpdate.md) to everyone in the chat.
 
 On some platforms, such as "broadcast channels," it is technically impossible
 for subscribers to discover or send updates to each other directly.
 In those cases, only the app sender can distribute updates globally.
 
 
+
 ## Example using selfAddr and selfName
 
 Here is a simple chat app that sends out a reply using the display names

src-docs/spec/sendUpdate.md

@@ -5,10 +5,11 @@ window.webxdc.sendUpdate(update, descr);
 ```
 
 Send an update to peers. 
-If `webxdc.canSendUpdatesToAllPeers` is true, the update is sent to all peers.
-If `webxdc.canSendUpdatesToAllPeers` is false, the update is only sent to the app sender
+If `webxdc.canOnlySendUpdatesToAppSender` is false, the update is sent to all peers.
+If `webxdc.canOnlySendUpdatesToAppSender` is true, the update is only sent to the app sender
 (the peer with the address `webxdc.appSenderAddr`).
 
+
 All receiving peers, including the sending one,
 will receive the update by the callback given to [`setUpdateListener()`](./setUpdateListener.html).