fix: skip JSX comments in HTML template generation

JSX comments {/* ... */} were generating anchor placeholders (<!--0-->)
in the HTML output even though Analyzer correctly skipped them for
binding index calculations. This mismatch caused rendering artifacts.

HtmlGenerator.JSXExpressionContainer now checks for JSXEmptyExpression
(which includes comments) and skips them, matching Analyzer behavior.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: martypdx

packages/thoth/transform/HtmlGenerator.js

@@ -93,6 +93,8 @@ export class HtmlGenerator extends Generator {
 
     // {...}
     JSXExpressionContainer(node, state) {
+        // Skip empty expressions (comments: {/* ... */})
+        if(node.expression?.type === 'JSXEmptyExpression') return;
         state.write(this.childReplace);
     }
 

packages/thoth/transform/template-generators.test.js

@@ -246,6 +246,20 @@ describe('render generator', () => {
         expect(code).toMatchInlineSnapshot(`"__renderer("a84dfd44", null, null, false, \`<p>static</p>\`)"`);
     });
 
+    test('jsx comments are ignored', ({ compile, expect }) => {
+        // JSX comments {/* ... */} should not generate anchor placeholders
+        const code = compile(`({ title }) => <div>
+            {/* Title is optional */}
+            {title && <h1>{title}</h1>}
+        </div>`);
+
+        // Only one <!--0--> for the conditional, none for the comment
+        expect(code).toMatchInlineSnapshot(`"__renderer("77ff2813", g24227028, b6b86b273, false, \`<div>
+            
+            <!--0-->
+        </div>\`)"`);
+    });
+
 
     test('props and elements', ({ compile, expect }) => {
         const code = compile(`const t = <p className={"className"}>