feat: add prelaunch site controls and refresh branding

docs/DEPLOYMENT.md

@@ -121,6 +121,46 @@ existing embedded-database connection instead of opening the locked database
 from a second process. The endpoint runs automated system messages, Oversight
 consolidation, and email digest checks and is not published through a host port.
 
+## Prelaunch operation
+
+The launch-control migration creates `site_launch_settings` with these defaults
+for a database that does not contain the row:
+
+- Coming Soon: enabled
+- Account creation: enabled
+- News, Database, Builds, Guides, and Builder: enabled
+
+The migration uses an insert-if-missing seed. Later deployments preserve the
+operator's settings, and configuration changes take effect without a restart.
+A full environment bootstrap copies the source row. Canonical ISAC game-data
+imports leave the target environment's launch settings unchanged.
+
+Use this operator flow after the first deployment:
+
+1. Open `/sign-in`; the launch gate keeps that route available.
+2. Sign in with an existing Administrator account.
+3. Open ISAC → System Configuration → Site Controls.
+4. Set account creation and public-section availability.
+5. Review the complete change set, then confirm it.
+6. Use `PREVIEW PAGE` to inspect `/coming-soon` with the authenticated
+   `ENTER FULL SITE` return action. The preview lists each section's current
+   availability.
+7. Verify `/coming-soon` and the affected public routes in a signed-out browser
+   session before public release. Sign in and verify the same disabled routes
+   remain unavailable.
+
+Keep Coming Soon enabled while preparing production. Section controls can be
+set in advance because the launch gate takes precedence for signed-out traffic.
+Set Account Creation to Disabled if prelaunch access must remain limited to
+existing identities. Switch the Launch Gate to Public Launch after verification.
+Disabled sections remain absent from navigation and unavailable by direct URL
+for every user, including authenticated agents. Authentication bypasses only
+the Coming Soon gate.
+
+Turn Coming Soon on to restore the promotional gate. Site-control changes append
+`system_configuration / site_access.updated` audit events, including the
+operator and complete before/after settings.
+
 ## Initial development-data bootstrap
 
 Initialize the first staging release from the development database, including