init: arcadia-admin — admin webapp for arcadia-core, cloned from vibespace

Initial commit. Spun up via the docs/STARTER.md recipe: cp from vibespace,
reset git, rename package, set brand to "Arcadia Admin" with Shield icon
in app/lib/identity.ts.

Inherits the full Crema sibling-lib wiring including @crema/arcadia-client
(typed HTTP + Phoenix Channels realtime against arcadia-core) and
@crema/arcadia-auth-ui (login/signup/password-reset/2FA forms). The /login
route already renders <LoginForm>; <ArcadiaProvider> in app/root.tsx reads
VITE_ARCADIA_URL (default localhost:4000) and VITE_ARCADIA_TENANT (default
"default").

CLAUDE.md and README rewritten to frame this as the admin app for
arcadia-core. docs/STARTER.md removed — arcadia-admin is a leaf consumer,
not a downstream starter.

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

app/components/ui/slider.tsx

@@ -0,0 +1,52 @@
+import { Slider as SliderPrimitive } from "@base-ui/react/slider"
+
+import { cn } from "~/lib/utils"
+
+function Slider({
+  className,
+  defaultValue,
+  value,
+  min = 0,
+  max = 100,
+  ...props
+}: SliderPrimitive.Root.Props) {
+  const _values = Array.isArray(value)
+    ? value
+    : Array.isArray(defaultValue)
+      ? defaultValue
+      : [min, max]
+
+  return (
+    <SliderPrimitive.Root
+      className={cn("data-horizontal:w-full data-vertical:h-full", className)}
+      data-slot="slider"
+      defaultValue={defaultValue}
+      value={value}
+      min={min}
+      max={max}
+      thumbAlignment="edge"
+      {...props}
+    >
+      <SliderPrimitive.Control className="relative flex w-full touch-none items-center select-none data-disabled:opacity-50 data-vertical:h-full data-vertical:min-h-40 data-vertical:w-auto data-vertical:flex-col">
+        <SliderPrimitive.Track
+          data-slot="slider-track"
+          className="relative grow overflow-hidden rounded-full bg-muted select-none data-horizontal:h-1 data-horizontal:w-full data-vertical:h-full data-vertical:w-1"
+        >
+          <SliderPrimitive.Indicator
+            data-slot="slider-range"
+            className="bg-primary select-none data-horizontal:h-full data-vertical:w-full"
+          />
+        </SliderPrimitive.Track>
+        {Array.from({ length: _values.length }, (_, index) => (
+          <SliderPrimitive.Thumb
+            data-slot="slider-thumb"
+            key={index}
+            className="relative block size-3 shrink-0 rounded-full border border-ring bg-white ring-ring/50 transition-[color,box-shadow] select-none after:absolute after:-inset-2 hover:ring-3 focus-visible:ring-3 focus-visible:outline-hidden active:ring-3 disabled:pointer-events-none disabled:opacity-50"
+          />
+        ))}
+      </SliderPrimitive.Control>
+    </SliderPrimitive.Root>
+  )
+}
+
+export { Slider }