Add persistent context files and cleanup stale references

- Add CONTEXT.md: Full infrastructure documentation with architecture diagram,
  routing table, network details, common operations, and important limitations
- Add CLAUDE.md: Project-level context for AI agents working in this codebase
- Add global-claude-md/CLAUDE.md: User-level global context for ~/.claude/
- Delete nginx-ai-proxy.conf: Unused, Caddy replaced nginx on big-server
- Update deploy.sh: Remove stale nginx setup step, update domain to ai.ein-softworks.com
- Update README.md: Remove nginx-ai-proxy.conf from files list, update domain,
  and remove leaked auth token from example

Context files provide persistent reference for AI coding sessions across
all projects and the ein-ai-proxy codebase specifically.

README.md

@@ -39,7 +39,7 @@ Add to `~/.claude/settings.json`:
 {
   "env": {
     "ANTHROPIC_BASE_URL": "https://ai.ein-softworks.com",
-    "ANTHROPIC_AUTH_TOKEN": "2d6aca1161e8ad8451c3c1247edf037b736dd7054fc2fab9e35adee313fdba5c",
+    "ANTHROPIC_AUTH_TOKEN": "your-proxy-auth-token",
     "API_TIMEOUT_MS": "3000000"
   }
 }
@@ -51,7 +51,7 @@ Add to `~/.claude/settings.json`:
 2. Set API Provider to **Anthropic**
 3. Enter your proxy auth token as the API Key
 4. Check **Use custom base URL**
-5. Enter `https://ai.maybe.zone`
+5. Enter `https://ai.ein-softworks.com`
 
 ## Switching models
 
@@ -63,8 +63,9 @@ From Claude Code, the default Sonnet model routes to GLM-4.7. To use Opus for a
 - `config.json` — Your API keys and auth token (gitignored)
 - `config.example.json` — Template config
 - `ein-ai-proxy.service` — Systemd unit file
-- `nginx-ai-proxy.conf` — Nginx reverse proxy config
 - `deploy.sh` — Deployment script
+- `CLAUDE.md` — Project-level context for AI agents
+- `CONTEXT.md` — Full infrastructure documentation
 
 ## License