fix(types): repair typecheck after oxlint safe autofix

The safe --fix introduced three type issues:

1. unicorn/prefer-set-has rewrote array literals to `new Set(...)`
   without updating the `T[]` type annotation — broken assignment.
   Fix type to `Set<T>` in logger.ts and agent-manager.ts.

2. unicorn/no-array-reverse changed `.reverse()` → `.toReversed()`
   (ES2023). Bump `lib` to ES2023 in tsconfig.base.json and
   tsconfig.server.json. Target stays at ES2020 — Node 20 supports
   the methods natively, no downlevel needed.

3. preserve-caught-error added `new Error(msg, { cause })` (ES2022),
   also covered by the lib bump.

tsconfig.base.json

@@ -1,7 +1,7 @@
 {
   "compilerOptions": {
     "target": "ES2020",
-    "lib": ["ES2020"],
+    "lib": ["ES2023"],
     "module": "ESNext",
     "moduleResolution": "bundler",
     "strict": true,