fix(deps): upgrade vulnerable dependencies

- @typescript-eslint/* v6 → v8 (fixes minimatch ReDoS, CVE high)
- vitest v1 → v4 (fixes rollup path traversal, vite CVE)
- flatted → 3.4.2 (fixes prototype pollution, CVE high)
- picomatch → 2.3.2 (fixes method injection, CVE medium)
- Update Octokit mocks to use class syntax for vitest v4
- Update eslint config for typescript-eslint v8
- Fix no-base-to-string lint error in logger

Author: PaulDuvall

skill/.eslintrc.json

@@ -9,7 +9,7 @@
   "extends": [
     "eslint:recommended",
     "plugin:@typescript-eslint/recommended",
-    "plugin:@typescript-eslint/recommended-requiring-type-checking",
+    "plugin:@typescript-eslint/recommended-type-checked",
     "prettier"
   ],
   "rules": {