feat(08-02): create CategoryFilterDropdown component

- Searchable dropdown with Lucide icons per category option
- "All categories" as first option with null value
- Click-outside and Escape key dismissal
- Clear button on trigger when category selected
- Auto-focus search input when dropdown opens
- State reset (search text) when dropdown closes

src/client/components/CategoryFilterDropdown.tsx

@@ -0,0 +1,198 @@
+import { useEffect, useRef, useState } from "react";
+import { LucideIcon } from "../lib/iconData";
+
+interface CategoryFilterDropdownProps {
+	value: number | null;
+	onChange: (value: number | null) => void;
+	categories: Array<{ id: number; name: string; icon: string }>;
+}
+
+export function CategoryFilterDropdown({
+	value,
+	onChange,
+	categories,
+}: CategoryFilterDropdownProps) {
+	const [isOpen, setIsOpen] = useState(false);
+	const [searchText, setSearchText] = useState("");
+	const containerRef = useRef<HTMLDivElement>(null);
+	const searchInputRef = useRef<HTMLInputElement>(null);
+
+	const selectedCategory = categories.find((c) => c.id === value);
+
+	const filteredCategories = categories.filter((c) =>
+		c.name.toLowerCase().includes(searchText.toLowerCase()),
+	);
+
+	// Click-outside dismiss
+	useEffect(() => {
+		function handleClickOutside(e: MouseEvent) {
+			if (
+				containerRef.current &&
+				!containerRef.current.contains(e.target as Node)
+			) {
+				setIsOpen(false);
+				setSearchText("");
+			}
+		}
+		document.addEventListener("mousedown", handleClickOutside);
+		return () => document.removeEventListener("mousedown", handleClickOutside);
+	}, []);
+
+	// Escape key dismiss
+	useEffect(() => {
+		function handleKeyDown(e: KeyboardEvent) {
+			if (e.key === "Escape" && isOpen) {
+				setIsOpen(false);
+				setSearchText("");
+			}
+		}
+		document.addEventListener("keydown", handleKeyDown);
+		return () => document.removeEventListener("keydown", handleKeyDown);
+	}, [isOpen]);
+
+	// Auto-focus search input when dropdown opens
+	useEffect(() => {
+		if (isOpen && searchInputRef.current) {
+			searchInputRef.current.focus();
+		}
+	}, [isOpen]);
+
+	function handleSelect(categoryId: number | null) {
+		onChange(categoryId);
+		setIsOpen(false);
+		setSearchText("");
+	}
+
+	return (
+		<div ref={containerRef} className="relative">
+			{/* Trigger button */}
+			<button
+				type="button"
+				onClick={() => setIsOpen((prev) => !prev)}
+				className="flex items-center gap-2 px-3 py-2 border border-gray-200 rounded-lg text-sm bg-white hover:bg-gray-50 transition-colors whitespace-nowrap"
+			>
+				{selectedCategory ? (
+					<>
+						<LucideIcon
+							name={selectedCategory.icon}
+							size={14}
+							className="text-gray-500 shrink-0"
+						/>
+						<span className="text-gray-900">{selectedCategory.name}</span>
+					</>
+				) : (
+					<span className="text-gray-600">All categories</span>
+				)}
+				{selectedCategory ? (
+					<button
+						type="button"
+						onClick={(e) => {
+							e.stopPropagation();
+							onChange(null);
+						}}
+						className="ml-1 text-gray-400 hover:text-gray-600"
+					>
+						<svg
+							className="w-3.5 h-3.5"
+							fill="none"
+							stroke="currentColor"
+							viewBox="0 0 24 24"
+						>
+							<path
+								strokeLinecap="round"
+								strokeLinejoin="round"
+								strokeWidth={2}
+								d="M6 18L18 6M6 6l12 12"
+							/>
+						</svg>
+					</button>
+				) : (
+					<svg
+						className="w-4 h-4 text-gray-400"
+						fill="none"
+						stroke="currentColor"
+						viewBox="0 0 24 24"
+					>
+						<path
+							strokeLinecap="round"
+							strokeLinejoin="round"
+							strokeWidth={2}
+							d="M19 9l-7 7-7-7"
+						/>
+					</svg>
+				)}
+			</button>
+
+			{/* Dropdown panel */}
+			{isOpen && (
+				<div className="absolute right-0 z-20 mt-1 min-w-[220px] bg-white border border-gray-200 rounded-lg shadow-lg">
+					{/* Search input */}
+					<div className="p-2 border-b border-gray-100">
+						<input
+							ref={searchInputRef}
+							type="text"
+							placeholder="Search categories..."
+							value={searchText}
+							onChange={(e) => setSearchText(e.target.value)}
+							className="w-full px-2.5 py-1.5 border border-gray-200 rounded text-sm focus:outline-none focus:ring-2 focus:ring-gray-400 focus:border-transparent"
+						/>
+					</div>
+
+					{/* Option list */}
+					<ul className="max-h-60 overflow-y-auto py-1">
+						{/* All categories option */}
+						{(searchText === "" ||
+							"all categories".includes(searchText.toLowerCase())) && (
+							<li>
+								<button
+									type="button"
+									onClick={() => handleSelect(null)}
+									className={`w-full text-left px-3 py-2 text-sm cursor-pointer hover:bg-gray-50 ${
+										value === null
+											? "bg-gray-50 font-medium text-gray-900"
+											: "text-gray-700"
+									}`}
+								>
+									All categories
+								</button>
+							</li>
+						)}
+
+						{/* Category options */}
+						{filteredCategories.map((cat) => (
+							<li key={cat.id}>
+								<button
+									type="button"
+									onClick={() => handleSelect(cat.id)}
+									className={`w-full text-left px-3 py-2 text-sm cursor-pointer flex items-center gap-2 hover:bg-gray-50 ${
+										cat.id === value
+											? "bg-gray-50 font-medium text-gray-900"
+											: "text-gray-700"
+									}`}
+								>
+									<LucideIcon
+										name={cat.icon}
+										size={16}
+										className="text-gray-500 shrink-0"
+									/>
+									{cat.name}
+								</button>
+							</li>
+						))}
+
+						{/* No results */}
+						{filteredCategories.length === 0 &&
+							!(
+								searchText === "" ||
+								"all categories".includes(searchText.toLowerCase())
+							) && (
+								<li className="px-3 py-2 text-sm text-gray-400">
+									No categories found
+								</li>
+							)}
+					</ul>
+				</div>
+			)}
+		</div>
+	);
+}