fix(runner): align editable draft bounds with Unicode schema lengths

Count initialText Unicode code points consistently in TypeScript, Zod, JSON Schema and Rust. Keep submitted-answer UTF-16 limits unchanged, with mixed BMP and astral boundary tests inside the wire byte cap.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

packages/shared/src/validators/issue.test.ts

@@ -643,8 +643,15 @@ describe("persisted canonical question initial text", () => {
       expect(paperclipQuestionSetPayloadSchema.parse(input({ initialText }))).toEqual(input({ initialText }));
     }
   });
+  it("counts mixed BMP and astral draft text like JSON Schema", () => {
+    for (const codePoints of [100_000, 100_001]) {
+      const initialText = "a".repeat(codePoints - 1) + "😀";
+      expect(Buffer.byteLength(JSON.stringify(input({ initialText })))).toBeLessThan(196 * 1024);
+      expect(paperclipQuestionSetPayloadSchema.safeParse(input({ initialText })).success).toBe(codePoints === 100_000);
+    }
+  });
   it("rejects non-text modes and unbounded or nonstring defaults", () => {
-    for (const initialText of [null, 1, "x".repeat(100_001), "😀".repeat(50_001)]) {
+    for (const initialText of [null, 1, "x".repeat(100_001), "a".repeat(100_000) + "😀"]) {
       expect(paperclipQuestionSetPayloadSchema.safeParse(input({ initialText })).success).toBe(false);
     }
     expect(paperclipQuestionSetPayloadSchema.safeParse(input({ answerMode: "single_select", options: [{ id: "a", label: "A" }], initialText: "a" })).success).toBe(false);

packages/shared/src/validators/issue.ts

@@ -1251,7 +1251,7 @@ const paperclipQuestionSchema = z
     helpText: z.string().max(4000).optional(),
     required: z.boolean(),
     answerMode: z.enum(["single_select", "multi_select", "text"]),
-    initialText: z.string().max(100000).optional(),
+    initialText: z.string().refine(value => value.length <= 200000 && Array.from(value).length <= 100000, "initial text exceeds 100000 Unicode code points").optional(),
     options: z.array(paperclipQuestionOptionSchema).max(128).optional(),
     customAnswer: z
       .object({