docs: update README and .env.example for SMTP removal

SMTP configuration is now managed at runtime via the vendor admin UI.
Remove SMTP config reference table, CLI flags from silent install example,
and env vars from .env.example.

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

README.md

@@ -140,17 +140,11 @@ The Docker socket is required for tenant provisioning (SaaS mode) — the platfo
 
 For private registries, provide credentials and the installer runs `docker login` before pulling. The registry prefix is applied to all container images.
 
-### SMTP (SaaS Mode)
+### Email / SMTP
 
-| Setting | CLI Flag | Env Var | Config Key | Default |
-|---------|----------|---------|------------|---------|
-| SMTP host | `--smtp-host` | `SMTP_HOST` | `smtp_host` | — |
-| SMTP port | `--smtp-port` | `SMTP_PORT` | `smtp_port` | `587` |
-| SMTP username | `--smtp-user` | `SMTP_USER` | `smtp_user` | — |
-| SMTP password | `--smtp-pass` | `SMTP_PASS` | `smtp_pass` | — |
-| From email | `--smtp-from-email` | `SMTP_FROM_EMAIL` | `smtp_from_email` | `noreply@<PUBLIC_HOST>` |
+Email connector configuration (SMTP, SES, etc.) is managed at runtime via the vendor admin UI at `/vendor/email`. The installer does not configure email delivery.
 
-SMTP is required for self-service sign-up (email verification codes). Without it, only admin-created users can sign in.
+Self-service registration is disabled by default and is enabled automatically when the admin configures an email connector.
 
 ### Monitoring
 
@@ -246,9 +240,6 @@ All services share a single hostname. Routing:
   --tls-mode=custom \
   --cert-file=/etc/ssl/cert.pem \
   --key-file=/etc/ssl/key.pem \
-  --smtp-host=smtp.example.com \
-  --smtp-user=noreply@example.com \
-  --smtp-pass=mailpass \
   --registry=registry.example.com/cameleer \
   --registry-user=deploy \
   --registry-token=ghp_xxx

templates/.env.example

@@ -61,14 +61,10 @@ SAAS_ADMIN_PASS=CHANGE_ME
 # BOOTSTRAP_TOKEN=CHANGE_ME
 
 # ============================================================
-# SMTP (for email verification during registration)
+# Email / SMTP
 # ============================================================
-# Required for self-service sign-up. Without SMTP, only admin-created users can sign in.
-SMTP_HOST=
-SMTP_PORT=587
-SMTP_USER=
-SMTP_PASS=
-SMTP_FROM_EMAIL=noreply@cameleer.io
+# Email connector configuration is managed at runtime via the vendor
+# admin UI (Email Connector page at /vendor/email). No SMTP env vars needed.
 
 # ============================================================
 # TLS