chore: fully embrace TypeScript 6 — drop ignoreDeprecations, use module Node16

Replace deprecated moduleResolution "node" + module "commonjs" with
module "Node16" + moduleResolution "Node16", remove ignoreDeprecations.
No behaviour change; build and tests clean.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: saby1101

tsconfig.json

@@ -12,9 +12,8 @@
     "forceConsistentCasingInFileNames": true,
     "importHelpers": false,
     "lib": ["ES2020"],
-    "module": "commonjs",
-    "ignoreDeprecations": "6.0",
-    "moduleResolution": "node",
+    "module": "Node16",
+    "moduleResolution": "Node16",
     "newLine": "LF",
     "noFallthroughCasesInSwitch": true,
     "noImplicitAny": true,