feat: add board background patterns (dots, grid, gradient) with settings dropdown

src/components/board/BoardView.tsx

@@ -1,4 +1,4 @@
-import { useState, useRef, useEffect, useCallback } from "react";
+import React, { useState, useRef, useEffect, useCallback } from "react";
 import { Plus } from "lucide-react";
 import {
   DndContext,
@@ -30,6 +30,30 @@ function findColumnByCardId(board: Board, cardId: string) {
   return board.columns.find((col) => col.cardIds.includes(cardId));
 }
 
+function getBoardBackground(board: Board): React.CSSProperties {
+  const bg = board.settings.background;
+  if (bg === "dots") {
+    return {
+      backgroundImage: `radial-gradient(circle, currentColor 1px, transparent 1px)`,
+      backgroundSize: "20px 20px",
+      color: "oklch(50% 0 0 / 5%)",
+    };
+  }
+  if (bg === "grid") {
+    return {
+      backgroundImage: `linear-gradient(currentColor 1px, transparent 1px), linear-gradient(90deg, currentColor 1px, transparent 1px)`,
+      backgroundSize: "24px 24px",
+      color: "oklch(50% 0 0 / 5%)",
+    };
+  }
+  if (bg === "gradient") {
+    return {
+      background: `linear-gradient(135deg, ${board.color}08, ${board.color}03, transparent)`,
+    };
+  }
+  return {};
+}
+
 export function BoardView() {
   const board = useBoardStore((s) => s.board);
   const addColumn = useBoardStore((s) => s.addColumn);
@@ -296,7 +320,7 @@ export function BoardView() {
         items={columnIds}
         strategy={horizontalListSortingStrategy}
       >
-        <div className="flex h-full overflow-x-auto" style={{ gap: `calc(1.5rem * var(--density-factor))`, padding: `calc(1.5rem * var(--density-factor))` }}>
+        <div className="flex h-full overflow-x-auto" style={{ gap: `calc(1.5rem * var(--density-factor))`, padding: `calc(1.5rem * var(--density-factor))`, ...getBoardBackground(board) }}>
           {board.columns.map((column) => (
             <KanbanColumn
               key={column.id}

src/components/layout/TopBar.tsx

@@ -1,11 +1,20 @@
 import { useState, useRef, useEffect, useCallback } from "react";
-import { ArrowLeft, Settings, Search, Undo2, Redo2 } from "lucide-react";
+import { ArrowLeft, Settings, Search, Undo2, Redo2, SlidersHorizontal } from "lucide-react";
 import { Button } from "@/components/ui/button";
 import {
   Tooltip,
   TooltipTrigger,
   TooltipContent,
 } from "@/components/ui/tooltip";
+import {
+  DropdownMenu,
+  DropdownMenuContent,
+  DropdownMenuItem,
+  DropdownMenuSub,
+  DropdownMenuSubContent,
+  DropdownMenuSubTrigger,
+  DropdownMenuTrigger,
+} from "@/components/ui/dropdown-menu";
 import { useAppStore } from "@/stores/app-store";
 import { useBoardStore } from "@/stores/board-store";
 
@@ -158,6 +167,37 @@ export function TopBar() {
             </Tooltip>
           </>
         )}
+        {isBoardView && board && (
+          <DropdownMenu>
+            <DropdownMenuTrigger asChild>
+              <Button
+                variant="ghost"
+                size="icon-sm"
+                className="text-pylon-text-secondary hover:text-pylon-text"
+              >
+                <SlidersHorizontal className="size-4" />
+              </Button>
+            </DropdownMenuTrigger>
+            <DropdownMenuContent align="end">
+              <DropdownMenuSub>
+                <DropdownMenuSubTrigger>Background</DropdownMenuSubTrigger>
+                <DropdownMenuSubContent>
+                  {(["none", "dots", "grid", "gradient"] as const).map((bg) => (
+                    <DropdownMenuItem
+                      key={bg}
+                      onClick={() => useBoardStore.getState().updateBoardSettings({ ...board.settings, background: bg })}
+                    >
+                      {bg.charAt(0).toUpperCase() + bg.slice(1)}
+                      {board.settings.background === bg && (
+                        <span className="ml-auto text-pylon-accent">*</span>
+                      )}
+                    </DropdownMenuItem>
+                  ))}
+                </DropdownMenuSubContent>
+              </DropdownMenuSub>
+            </DropdownMenuContent>
+          </DropdownMenu>
+        )}
         {savingStatus && (
           <span className="mr-2 font-mono text-xs text-pylon-text-secondary">
             {savingStatus}