docs(deploy): flag buildmymcp.com vs buildmymcpserver.com domain mismatch

The request said buildmymcp.com; the GoDaddy tab and the repo are named
buildmymcpserver.com. Added a top-of-file callout so the domain is resolved
before any DNS/nameserver change rather than baked in wrong.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

DEPLOY.md

@@ -1,4 +1,4 @@
-# Deploying buildmymcp.com
+# Deploying the app
 
 End-to-end runbook: domain → DNS → server → live, plus Google login.
 
@@ -9,6 +9,26 @@ the host over SSH.
 
 ---
 
+## ⚠️ FIRST: confirm the domain name
+
+The request said **`buildmymcp.com`**. But the open GoDaddy tab and this
+repository are both named **`buildmymcpserver.com`** — that is the domain you
+appear to actually own.
+
+**These are two different domains.** Decide which one before doing anything:
+
+- If the live domain is **`buildmymcpserver.com`** — do a find-and-replace of
+  `buildmymcp.com` → `buildmymcpserver.com` across this file and
+  `.env.production.example` before you start. `api.buildmymcp.com` becomes
+  `api.buildmymcpserver.com`, etc.
+- If you intend to register and use the shorter **`buildmymcp.com`** — register
+  it at GoDaddy first, then this file is correct as written.
+
+Every hostname below uses `buildmymcp.com` as a placeholder. It must match the
+domain you put into Cloudflare in step 1.
+
+---
+
 ## 0. What you are deploying
 
 Five services, defined in `docker-compose.prod.yml`: