chore(deps): support TypeScript 6 (widen peer to ^5 || ^6)

- Add typescript ^6.0.0 as devDependency for verified builds
- Widen peerDependency to ^5 || ^6 to keep TS 5 consumers supported
- tsconfig.build.json: set explicit rootDir (required by TS 6 when outDir is set)
- tsconfig.build.json: replace deprecated moduleResolution "node" with "bundler"

tsconfig.build.json

@@ -5,7 +5,8 @@
     "emitDeclarationOnly": true,
     "declaration": true,
     "outDir": "./dist",
-    "moduleResolution": "node",
+    "rootDir": "./src",
+    "moduleResolution": "bundler",
     "verbatimModuleSyntax": false
   },
   "include": [