feat(import/markdown): normalize non-breaking spaces

src/services/export/markdown.spec.ts

@@ -226,4 +226,16 @@ describe("Markdown export", () => {
         expect(markdownExportService.toMarkdown(html)).toBe(expected);
     });
 
+    it("converts   to character", () => {
+        const html = /*html*/`<p>Hello&nbsp;world.</p>`;
+        const expected = `Hello\u00a0world.`;
+        expect(markdownExportService.toMarkdown(html)).toBe(expected);
+    });
+
+    it("preserves non-breaking space character", () => {
+        const html = /*html*/`<p>Hello\u00adworld.</p>`;
+        const expected = `Hello\u00adworld.`;
+        expect(markdownExportService.toMarkdown(html)).toBe(expected);
+    });
+
 });

src/services/import/markdown.spec.ts

@@ -133,4 +133,16 @@ second line 2</code></pre><ul><li>Hello</li><li>world</li></ul><ol><li>Hello</li
         expect(markdownService.renderToHtml(input, "Title")).toStrictEqual(expected);
     });
 
+    it("preserves &nbsp;", () => {
+        const input = `Hello&nbsp;world.`;
+        const expected = /*html*/`<p>Hello&nbsp;world.</p>`;
+        expect(markdownService.renderToHtml(input, "Title")).toStrictEqual(expected);
+    });
+
+    it("converts non-breaking space character to &nbsp;", () => {
+        const input = `Hello\u00a0world.`;
+        const expected = /*html*/`<p>Hello&nbsp;world.</p>`;
+        expect(markdownService.renderToHtml(input, "Title")).toStrictEqual(expected);
+    });
+
 });

src/services/import/markdown.ts

@@ -87,6 +87,9 @@ function renderToHtml(content: string, title: string) {
     // Remove slash for self-closing tags to match CKEditor's approach.
     html = html.replace(/<(\w+)([^>]*)\s+\/>/g, "<$1$2>");
 
+    // Normalize non-breaking spaces to entity.
+    html = html.replaceAll("\u00a0", "&nbsp;");
+
     return html;
 }