fix(ai-cli): install current upstream Codex and Claude releases

- Pin official Codex 0.161.0 and Claude Code 2.1.292 binaries
- Preserve Codex helpers and Claude's NixOS compatibility wrapper
- Add an updater for stable upstream versions and checksums
- Document CLI updates independently of stable NixOS inputs

packages/ai-cli-versions.json

@@ -0,0 +1,10 @@
+{
+  "codex": {
+    "version": "0.161.0",
+    "sha256": "04d8ab9dbcb9df0edf3c67dca5072a374babfdf762a9bc4ae649ae140b8e2cf0"
+  },
+  "claude-code": {
+    "version": "2.1.292",
+    "sha256": "a967e7b1d8b4e47ee421d5433027880347952b0c0857abf880e2c942a4ec93b3"
+  }
+}