feat: remove "Initial Checkpoint" terminology, use "Checkpoint" consistently

Author: roomote

webview-ui/src/components/chat/checkpoints/CheckpointSaved.tsx

@@ -37,9 +37,7 @@ export const CheckpointSaved = ({ checkpoint, ...props }: CheckpointSavedProps)
 		<div className="flex items-center justify-between">
 			<div className="flex gap-2">
 				<span className="codicon codicon-git-commit text-blue-400" />
-				<span className="font-bold">
-					{metadata.isFirst ? t("chat:checkpoint.initial") : t("chat:checkpoint.regular")}
-				</span>
+				<span className="font-bold">{t("chat:checkpoint.regular")}</span>
 				{isCurrent && <span className="text-muted text-sm">{t("chat:checkpoint.current")}</span>}
 			</div>
 			<CheckpointMenu {...props} checkpoint={metadata} />

webview-ui/src/i18n/locales/ca/chat.json

@@ -145,7 +145,6 @@
 		"streamingFailed": "API Streaming Failed"
 	},
 	"checkpoint": {
-		"initial": "Initial Checkpoint",
 		"regular": "Checkpoint",
 		"initializingWarning": "Still initializing checkpoint... If this takes too long, you can disable checkpoints in <settingsLink>settings</settingsLink> and restart your task.",
 		"menu": {