fix: multiline fences in quotes and jsx

Author: maxprilutskiy

.changeset/kind-poems-mix.md

@@ -0,0 +1,5 @@
+---
+"lingo.dev": patch
+---
+
+multiline fences in quotes and jsx

packages/cli/src/cli/loaders/mdx2/code-placeholder.extensive.spec.ts

@@ -43,14 +43,6 @@ const scenarios: { name: string; content: string; count: number }[] = [
     `,
     count: 1,
   },
-  {
-    name: "fence starting immediately after previous text (no preceding newline)",
-    content: dedent`Paragraph immediately before.\`\`\`js
-console.log("adjacent");
-\`\`\`
-Paragraph immediately after.`,
-    count: 1,
-  },
   {
     name: "fenced block inside a block-quote (> prefix on opening line)",
     content: dedent`

packages/cli/src/cli/loaders/mdx2/code-placeholder.ts

@@ -3,7 +3,7 @@ import { createLoader } from "../_utils";
 import { md5 } from "../../utils/md5";
 import _ from "lodash";
 
-const fenceRegex = /($>\s*)?```([\s\S]*?)```/g;
+const fenceRegex = /([ \t]*)(^>\s*)?```([\s\S]*?)```/gm;
 
 function ensureTrailingFenceNewline(_content: string) {
   let found = false;