Phase 4/5: host demos via Apache container behind Caddy

deploy/smb-demos: compose + runbook for the static demo host
(httpd on the proxy network, routed by Caddy at demos.mivanchenko.de).
Pending a DNS A record before Caddy can issue TLS.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

deploy/smb-demos/README.md

@@ -0,0 +1,14 @@
+# smb-demos — public demo hosting
+
+Apache container on the homelab host serving the two tier demos + chooser.
+
+- **Host path:** `/home/mivanchenko/smb-demos/` (compose) + `site/` (= `templates/landing/`)
+- **Network:** external `proxy` (shared with Caddy); Caddy reaches it as `smb-demos:80`
+- **Caddyfile block:** `demos.mivanchenko.de { reverse_proxy smb-demos:80\n  encode zstd gzip }`
+- **DNS:** needs an A record `demos.mivanchenko.de -> 188.193.49.3` (no wildcard)
+- **Reload Caddy after Caddyfile edit:** `docker exec caddy caddy reload --config /etc/caddy/Caddyfile`
+
+Update the live site after editing `templates/landing/`:
+`scp -r templates/landing/. n8n.mivanchenko.de:/home/mivanchenko/smb-demos/site/`
+
+Forms POST to `https://n8n.mivanchenko.de/webhook/lead-intake` (CORS allowedOrigins=*).