fix(backend): raise comment JSON byte limit to 40kb (#2348)

* fix(backend): raise comment JSON byte limit to 40kb

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* test(backend): bump byte-limit test payload above 40kb

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: gregberge

apps/backend/src/comment/validate.test.ts

@@ -379,7 +379,7 @@ describe("isCommentTooLarge", () => {
               marks: [
                 {
                   type: "link",
-                  attrs: { href: `https://example.com/${"a".repeat(25_000)}` },
+                  attrs: { href: `https://example.com/${"a".repeat(45_000)}` },
                 },
               ],
             },

apps/backend/src/comment/validate.ts

@@ -169,7 +169,7 @@ export function isCommentEmpty(value: JSONContent): boolean {
  * - depth protects recursive rendering from pathological nesting.
  */
 const MAX_COMMENT_CHARACTERS = 2_000;
-const MAX_COMMENT_JSON_BYTES = 20_000;
+const MAX_COMMENT_JSON_BYTES = 40_000;
 const MAX_COMMENT_NODES = 300;
 const MAX_COMMENT_DEPTH = 12;