A documentation link in the sidebar, and the footer points home

Documentation above Settings, opening in a new tab — the docs are read beside
the work, not instead of it. The footer's "Fluksio - <year>" links to
fluksio.com; the sidebar logo deliberately keeps going Home, since navigating a
running installation away to a marketing page is not what pressing it means.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

frontend/src/components/Sidebar/AppSidebar.tsx

@@ -1,6 +1,7 @@
 import {
   ArrowLeft,
   Bell,
+  BookOpen,
   FlaskConical,
   Home,
   KeyRound,
@@ -25,6 +26,15 @@ import useAuth from "@/hooks/useAuth"
 import { portalConfig } from "@/lib/portal"
 import { type Item, Main } from "./Main"
 
+/**
+ * Where the documentation is published.
+ *
+ * A constant rather than something derived: an installation reached over a LAN
+ * address, or at localhost, has no domain to build this from, and the docs are
+ * one site for all of them.
+ */
+const DOCS_URL = "https://docs.fluksio.com"
+
 const baseItems: Item[] = [
   // "Home" rather than "Dashboard": dashboards are their own thing now, and
   // the brain and the health screens are sections of Home rather than routes.
@@ -63,9 +73,18 @@ export function AppSidebar() {
       ]
     : withAdmin
 
+  // A new tab rather than a navigation: the docs are read beside the work,
+  // not instead of it.
+  const docs: Item = {
+    icon: BookOpen,
+    title: "Documentation",
+    onClick: () => window.open(DOCS_URL, "_blank", "noopener"),
+  }
+
   const footerItems: Item[] = portal
-    ? [{ icon: Settings, title: "Settings", path: "/settings" }]
+    ? [docs, { icon: Settings, title: "Settings", path: "/settings" }]
     : [
+        docs,
         { icon: Settings, title: "Settings", path: "/settings" },
         { icon: LogOut, title: "Log Out", onClick: logout },
       ]