Fix slow header, rebrand OAuth page, fix alpha-hub login callback

- Replace slow system_profiler/docker info with fast cached alternatives
- Single-line system info: cores · ram · docker
- Patch Pi OAuth callback page with Feynman branding
- Fix alpha-hub login: wait for server ready before opening browser, handle port conflicts, auto-close tab

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@companion-ai/feynman",
-  "version": "0.2.2",
+  "version": "0.2.3",
   "description": "Research-first CLI agent built on Pi and alphaXiv",
   "type": "module",
   "bin": {