feat: rebuild FilterBuilder with shadcn/ui components

Replace native HTML elements with design system components:
- Operator <select> → shadcn Select dropdown
- Field <input>+<datalist> → shadcn Select with all available fields
- Value input → shadcn Select (when suggestions available) or Input
- Date input (type="date") for before/after operators
- Remove button → shadcn Button variant="ghost"
- AND/OR toggle → shadcn Button variant="outline" with rounded-full

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/components/FilterBuilder.tsx

@@ -1,6 +1,7 @@
-import { useId } from 'react'
 import { Plus, X } from '@phosphor-icons/react'
 import { Button } from '@/components/ui/button'
+import { Input } from '@/components/ui/input'
+import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from '@/components/ui/select'
 import type { FilterCondition, FilterOp, FilterGroup, FilterNode } from '../types'
 
 const OPERATORS: { value: FilterOp; label: string }[] = [
@@ -15,6 +16,7 @@ const OPERATORS: { value: FilterOp; label: string }[] = [
 ]
 
 const NO_VALUE_OPS = new Set<FilterOp>(['is_empty', 'is_not_empty'])
+const DATE_OPS = new Set<FilterOp>(['before', 'after'])
 
 function isFilterGroup(node: FilterNode): node is FilterGroup {
   return 'all' in node || 'any' in node
@@ -32,49 +34,97 @@ function setGroupChildren(mode: 'all' | 'any', children: FilterNode[]): FilterGr
   return mode === 'all' ? { all: children } : { any: children }
 }
 
-/** Combobox-style field input with datalist autocomplete. */
-function FieldInput({ value, fields, onChange }: {
+function FieldSelect({ value, fields, onChange }: {
   value: string
   fields: string[]
   onChange: (v: string) => void
 }) {
-  const id = useId()
+  const isCustom = value !== '' && !fields.includes(value)
   return (
-    <>
-      <input
-        list={id}
-        className="h-8 rounded-md border border-input bg-background px-2 text-sm flex-1 min-w-0"
-        value={value}
-        onChange={(e) => onChange(e.target.value)}
-        placeholder="field"
-      />
-      <datalist id={id}>
-        {fields.map((f) => <option key={f} value={f} />)}
-      </datalist>
-    </>
+    <Select value={value} onValueChange={onChange}>
+      <SelectTrigger
+        size="sm"
+        className="h-8 min-w-[100px] flex-1 gap-1 border-input bg-background px-2 text-sm shadow-none"
+      >
+        <SelectValue placeholder="field" />
+      </SelectTrigger>
+      <SelectContent position="popper">
+        {isCustom && <SelectItem value={value}>{value}</SelectItem>}
+        {fields.map((f) => (
+          <SelectItem key={f} value={f}>{f}</SelectItem>
+        ))}
+      </SelectContent>
+    </Select>
   )
 }
 
-/** Combobox-style value input with autocomplete for known values. */
-function ValueInput({ value, suggestions, onChange }: {
+function OperatorSelect({ value, onChange }: {
+  value: FilterOp
+  onChange: (v: FilterOp) => void
+}) {
+  return (
+    <Select value={value} onValueChange={(v) => onChange(v as FilterOp)}>
+      <SelectTrigger
+        size="sm"
+        className="h-8 shrink-0 gap-1 border-input bg-background px-2 text-sm shadow-none"
+        style={{ minWidth: 120 }}
+      >
+        <SelectValue />
+      </SelectTrigger>
+      <SelectContent position="popper">
+        {OPERATORS.map((o) => (
+          <SelectItem key={o.value} value={o.value}>{o.label}</SelectItem>
+        ))}
+      </SelectContent>
+    </Select>
+  )
+}
+
+function ValueInput({ value, suggestions, isDateOp, onChange }: {
   value: string
   suggestions: string[]
+  isDateOp: boolean
   onChange: (v: string) => void
 }) {
-  const id = useId()
-  return (
-    <>
-      <input
-        list={id}
-        className="h-8 rounded-md border border-input bg-background px-2 text-sm flex-1 min-w-0"
-        placeholder="value"
+  if (isDateOp) {
+    return (
+      <Input
+        type="date"
+        className="h-8 flex-1 min-w-0 text-sm"
         value={value}
         onChange={(e) => onChange(e.target.value)}
       />
-      <datalist id={id}>
-        {suggestions.map((s) => <option key={s} value={s} />)}
-      </datalist>
-    </>
+    )
+  }
+
+  if (suggestions.length > 0) {
+    return (
+      <Select value={value} onValueChange={onChange}>
+        <SelectTrigger
+          size="sm"
+          className="h-8 flex-1 min-w-0 gap-1 border-input bg-background px-2 text-sm shadow-none"
+        >
+          <SelectValue placeholder="value" />
+        </SelectTrigger>
+        <SelectContent position="popper">
+          {value !== '' && !suggestions.includes(value) && (
+            <SelectItem value={value}>{value}</SelectItem>
+          )}
+          {suggestions.map((s) => (
+            <SelectItem key={s} value={s}>{s}</SelectItem>
+          ))}
+        </SelectContent>
+      </Select>
+    )
+  }
+
+  return (
+    <Input
+      className="h-8 flex-1 min-w-0 text-sm"
+      placeholder="value"
+      value={value}
+      onChange={(e) => onChange(e.target.value)}
+    />
   )
 }
 
@@ -86,37 +136,36 @@ function FilterRow({ condition, fields, valueSuggestions, onUpdate, onRemove }:
   onRemove: () => void
 }) {
   const suggestions = valueSuggestions(condition.field)
+  const isDateOp = DATE_OPS.has(condition.op)
   return (
     <div className="flex items-center gap-1.5">
-      <FieldInput
+      <FieldSelect
         value={condition.field}
         fields={fields}
         onChange={(v) => onUpdate({ ...condition, field: v })}
       />
-      <select
-        className="h-8 rounded-md border border-input bg-background px-2 text-sm shrink-0"
+      <OperatorSelect
         value={condition.op}
-        onChange={(e) => onUpdate({ ...condition, op: e.target.value as FilterOp })}
-      >
-        {OPERATORS.map((o) => (
-          <option key={o.value} value={o.value}>{o.label}</option>
-        ))}
-      </select>
+        onChange={(op) => onUpdate({ ...condition, op })}
+      />
       {!NO_VALUE_OPS.has(condition.op) && (
         <ValueInput
           value={String(condition.value ?? '')}
           suggestions={suggestions}
+          isDateOp={isDateOp}
           onChange={(v) => onUpdate({ ...condition, value: v })}
         />
       )}
-      <button
+      <Button
         type="button"
-        className="flex-shrink-0 rounded p-1 text-muted-foreground hover:text-foreground"
+        variant="ghost"
+        size="sm"
+        className="h-8 w-8 shrink-0 p-0 text-muted-foreground hover:text-foreground"
         onClick={onRemove}
         title="Remove filter"
       >
         <X size={14} />
-      </button>
+      </Button>
     </div>
   )
 }
@@ -159,26 +208,30 @@ function FilterGroupView({ group, fields, valueSuggestions, depth, onChange, onR
   return (
     <div className={depth > 0 ? 'ml-3 border-l-2 border-border pl-3 py-1' : ''}>
       <div className="flex items-center gap-2 mb-2">
-        <button
+        <Button
           type="button"
-          className="rounded-full border border-input bg-muted px-2.5 py-0.5 text-[11px] font-medium text-foreground cursor-pointer hover:bg-accent transition-colors"
+          variant="outline"
+          size="sm"
+          className="h-6 rounded-full px-2.5 text-[11px] font-medium"
           onClick={toggleMode}
           title={`Switch to ${mode === 'all' ? 'OR' : 'AND'}`}
         >
           {mode === 'all' ? 'AND' : 'OR'}
-        </button>
+        </Button>
         <span className="text-[11px] text-muted-foreground">
           {mode === 'all' ? 'Match all conditions' : 'Match any condition'}
         </span>
         {onRemove && (
-          <button
+          <Button
             type="button"
-            className="ml-auto rounded p-0.5 text-muted-foreground hover:text-foreground"
+            variant="ghost"
+            size="sm"
+            className="ml-auto h-6 w-6 p-0 text-muted-foreground hover:text-foreground"
             onClick={onRemove}
             title="Remove group"
           >
             <X size={12} />
-          </button>
+          </Button>
         )}
       </div>
       <div className="space-y-2">