chore: regenerate FULL_HELP_DOCS.md to drop stale xdr [CHANNEL] arg

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011WsVE7zXVYWKQkxMmhiqVV

Author: NicoMoli

FULL_HELP_DOCS.md

@@ -4145,7 +4145,7 @@ Encode a transaction envelope from JSON to XDR
 
 Decode and encode XDR
 
-**Usage:** `stellar xdr [CHANNEL] <COMMAND>`
+**Usage:** `stellar xdr <COMMAND>`
 
 ###### **Subcommands:**
 
@@ -4158,14 +4158,6 @@ Decode and encode XDR
 - `xfile` — Preprocess XDR .x files
 - `version` — Print version information
 
-###### **Arguments:**
-
-- `<CHANNEL>` — Channel of XDR to operate on
-
-  Default value: `+curr`
-
-  Possible values: `+curr`, `+next`
-
 ## `stellar xdr types`
 
 View information about types