feat: add multilingual dictation and simplify chat STT picker

src/core/locales/en.json

@@ -249,6 +249,8 @@
 	"Speech recognition language": "Speech recognition language",
 	"Auto": "Auto",
 	"System default": "System default",
+	"Multilingual": "Multilingual",
+	"Multi": "Multi",
 	"Global": "Global",
 	"Chat": "Chat",
 	"Graph view": "Graph view",
@@ -723,6 +725,7 @@
 	"thinkingLevel must be a string": "thinkingLevel must be a string",
 	"autoUpdate must be a boolean": "autoUpdate must be a boolean",
 	"{v0} must be \"en\" or \"ru\"": "{v0} must be \"en\" or \"ru\"",
+	"sttLanguage must be \"en\", \"ru\", or \"multi\"": "sttLanguage must be \"en\", \"ru\", or \"multi\"",
 	"{v0} must be an object": "{v0} must be an object",
 	"{v0}.model must be {provider, id}": "{v0}.model must be {provider, id}",
 	"{v0}.thinkingLevel must be a string": "{v0}.thinkingLevel must be a string",