feat(frontend): add FilterChips primitive

src/components/ui/filter-chips.tsx

@@ -0,0 +1,84 @@
+import { X } from "lucide-react";
+import { cn } from "@/lib/utils";
+
+export type FilterChipOption = { value: string; label: string };
+
+type FilterChipsProps = {
+  /** Available chip options. Order is preserved. */
+  options: FilterChipOption[];
+  /** Currently selected value, or null for "all". */
+  value: string | null;
+  /** Receives the new value, or null when "Clear" is pressed. */
+  onChange: (value: string | null) => void;
+  /** Optional eyebrow label rendered before the chips. */
+  eyebrow?: string;
+  className?: string;
+};
+
+/**
+ * Single-select filter chips.
+ * Voice: hairline-bordered pills; the active one fills with the electric
+ * blue accent at low opacity and lifts a hairline brighter than its
+ * peers. A small "Clear" pill appears once a value is set.
+ */
+export function FilterChips({
+  options,
+  value,
+  onChange,
+  eyebrow,
+  className,
+}: FilterChipsProps) {
+  return (
+    <div
+      className={cn(
+        "flex flex-wrap items-center gap-1.5",
+        className,
+      )}
+      role="radiogroup"
+      aria-label="Filter"
+    >
+      {eyebrow ? (
+        <span className="mr-1 text-[10.5px] font-semibold uppercase tracking-[0.18em] text-muted-foreground">
+          {eyebrow}
+        </span>
+      ) : null}
+      {options.map((opt) => {
+        const isActive = opt.value === value;
+        return (
+          <button
+            key={opt.value}
+            type="button"
+            role="radio"
+            aria-checked={isActive}
+            onClick={() => onChange(isActive ? null : opt.value)}
+            className={cn(
+              "h-7 rounded-full px-3 text-xs font-medium transition-colors",
+              "ring-1 ring-inset focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2 focus-visible:ring-offset-background",
+              isActive
+                ? "bg-accent/15 text-accent ring-accent/40 hover:bg-accent/20"
+                : "bg-transparent text-muted-foreground ring-border/60 hover:text-foreground hover:ring-border",
+            )}
+          >
+            {opt.label}
+          </button>
+        );
+      })}
+      {value !== null ? (
+        <button
+          type="button"
+          onClick={() => onChange(null)}
+          aria-label="Clear filter"
+          className={cn(
+            "h-7 rounded-full px-2.5 text-xs font-medium transition-colors",
+            "inline-flex items-center gap-1",
+            "text-muted-foreground hover:text-foreground",
+            "ring-1 ring-inset ring-border/40 hover:ring-border/60",
+          )}
+        >
+          <X className="h-3 w-3" strokeWidth={1.75} aria-hidden />
+          Clear
+        </button>
+      ) : null}
+    </div>
+  );
+}