Telegram/Discord: honor outbound mediaMaxMb uploads (#38065)

* Telegram: default media cap to 100MB

* Telegram: honor outbound mediaMaxMb

* Discord: add shared media upload cap

* Discord: pass mediaMaxMb to outbound sends

* Telegram: cover outbound media cap sends

* Discord: cover media upload cap config

* Docs: update Telegram media cap guide

* Docs: update Telegram config reference

* Changelog: note media upload cap fix

* Docs: note Discord upload cap behavior

docs/gateway/configuration-reference.md

@@ -183,7 +183,7 @@ WhatsApp runs through the gateway's web channel (Baileys Web). It starts automat
       streaming: "partial", // off | partial | block | progress (default: off)
       actions: { reactions: true, sendMessage: true },
       reactionNotifications: "own", // off | own | all
-      mediaMaxMb: 5,
+      mediaMaxMb: 100,
       retry: {
         attempts: 3,
         minDelayMs: 400,