chore(deps-dev): add @typescript/typescript6 for AST tooling; hold typescript at 6.x (TS7 has no JS compiler API)

package.json

@@ -214,6 +214,7 @@
     "@types/pdfkit": "^0.17.6",
     "@types/react": "^19.2.17",
     "@types/react-dom": "^19.2.3",
+    "@typescript/typescript6": "^6.0.2",
     "@vitest/coverage-v8": "^4.1.10",
     "esbuild": "0.28.1",
     "eslint": "^9.39.5",

scripts/check-design-system-contract.mjs

@@ -1,7 +1,7 @@
 import fs from "node:fs";
 import path from "node:path";
 import process from "node:process";
-import ts from "typescript";
+import ts from "@typescript/typescript6";
 
 import {
   LEGACY_TAP_CLASS,

scripts/design-system-contract-utils.mjs

@@ -1,4 +1,4 @@
-import ts from "typescript";
+import ts from "@typescript/typescript6";
 
 const LEGACY_TAP_TOKEN_SOURCE = String.raw`(?:[^\s:"'\x60]+:)*(?:h|w|min-h|min-w|size)-11`;
 

src/components/DocumentViewer.tsx

@@ -1873,7 +1873,7 @@ export function DocumentViewer({
   );
 
   const openSourcePreview = useCallback(
-    (options: { signal: AbortSignal; useCache: boolean }) => {
+    (options: { signal: AbortSignal; useCache: boolean }): Promise<SignedUrlResponsePayload> => {
       const endpoint = `/api/documents/${documentId}/signed-url`;
       const cached = options.useCache ? getCachedSignedUrl(endpoint) : null;
       return cached

tests/retrieval-owner-filter-guard.test.ts

@@ -1,7 +1,7 @@
 import { readFileSync, readdirSync } from "node:fs";
 import { join } from "node:path";
 
-import ts from "typescript";
+import ts from "@typescript/typescript6";
 import { describe, expect, it } from "vitest";
 
 // Guard for the retrieval owner-scope boundary (48h-review finding #3).