refactor(frontend): finish shadcn→custom primitive migration (green build)

- Remove tw-animate-css import + dead src/components/ui shadcn tree
- Convert 7 orphaned components (moderation, analysis, guild-selector,
  voice/activity-timeline, shared/empty+error) to new primitives
- Add missing moderation/view.tsx; analysis uses SearchPanel directly
- globals.css now uses new signal-driven ops-console tokens
- tsc --noEmit clean, next build green (11 routes), local smoke 200

services/frontend/src/components/primitives/select.tsx

@@ -0,0 +1,26 @@
+import { forwardRef, type SelectHTMLAttributes } from "react";
+import { cn } from "@/lib/utils";
+
+export interface SelectProps extends SelectHTMLAttributes<HTMLSelectElement> {
+  mono?: boolean;
+}
+
+export const Select = forwardRef<HTMLSelectElement, SelectProps>(
+  ({ className, mono, children, ...props }, ref) => (
+    <select
+      ref={ref}
+      className={cn(
+        "w-full bg-[var(--color-surface-2)] text-[var(--color-ink)] appearance-none cursor-pointer",
+        "rounded-[var(--radius-r-control)] border border-[var(--color-hairline)] px-3 py-2 text-sm",
+        "outline-none focus-visible:ring-2 focus-visible:ring-[var(--color-ring)] transition-colors",
+        "bg-[url('data:image/svg+xml;utf8,<svg xmlns=%22http://www.w3.org/2000/svg%22 width=%2212%22 height=%2212%22 fill=%22none%22 stroke=%22%23aaa%22 stroke-width=%222%22><path d=%22M2 4l4 4 4-4%22/></svg>')] bg-[length:12px] bg-[right_0.75rem_center] bg-no-repeat pr-9",
+        mono && "font-mono tracking-tight",
+        className,
+      )}
+      {...props}
+    >
+      {children}
+    </select>
+  ),
+);
+Select.displayName = "Select";