ci: initialize Dependabot rulesets for automated security patching

Author: softsideof

.github/dependabot.yml

@@ -0,0 +1,16 @@
+version: 2
+updates:
+  - package-ecosystem: "npm" 
+    directory: "/" 
+    schedule:
+      interval: "weekly"
+    ignore:
+      - dependency-name: "cross-fetch" # Locked version to maintain environment parity
+    groups:
+      dev-dependencies:
+        patterns:
+          - "ts-*"
+          - "jest"
+          - "@types/*"
+          - "typescript"
+          - "prettier"