후속 개선: 원격 썸네일·자동재연결, RAW 썸네일, 마퀴 선택, 이동 강건성

P1 원격 소스 UX:
- remote_thumbs: VFS 다운로드로 원격 썸네일 생성(이미지 EXIF 내장 우선,
  영상은 미디어서버 bridge URL로 ffmpeg Range 추출)
- 앱 시작 시 키체인 자격증명으로 원격 소스 자동 재연결
- fileops: physical_move에 Windows 공유위반 재시도

P3 그리드/포맷:
- RAW(cr2/nef/arw/dng 등) 내장 JPEG 프리뷰 추출 썸네일(scan_largest_jpeg)
- 그리드 마퀴(드래그 사각형) 다중선택
- .gitattributes 줄바꿈 정규화

Rust 테스트 51개 통과.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/features/grid/JustifiedGrid.tsx

@@ -13,10 +13,12 @@ import type { LayoutResult } from "./layout.worker";
 import LayoutWorker from "./layout.worker?worker";
 import {
   anchorIndex,
+  clearSelection,
   info,
   openLightbox,
   selected,
   selectSingle,
+  setSelectionFromIds,
   toggleSelect,
   selectRange,
   snapshot,
@@ -53,6 +55,8 @@ export const JustifiedGrid: Component = () => {
   const [scrollTop, setScrollTop] = createSignal(0);
   const [viewportH, setViewportH] = createSignal(600);
   const [containerW, setContainerW] = createSignal(0);
+  // 마퀴(드래그 사각형) 선택 — 콘텐츠 좌표계 [x1,y1,x2,y2]
+  const [marquee, setMarquee] = createSignal<[number, number, number, number] | null>(null);
 
   const worker = new LayoutWorker();
   let layoutSeq = 0;
@@ -244,11 +248,75 @@ export const JustifiedGrid: Component = () => {
     if (e.dataTransfer) e.dataTransfer.effectAllowed = "move";
   };
 
+  // ── 마퀴(드래그 사각형) 선택 ──
+  // 콘텐츠 좌표 = clientX - 컨테이너rect - 패딩(8) (+ y는 scrollTop)
+  const toContent = (clientX: number, clientY: number): [number, number] => {
+    const rect = containerRef!.getBoundingClientRect();
+    return [
+      clientX - rect.left - 8,
+      clientY - rect.top - 8 + containerRef!.scrollTop,
+    ];
+  };
+
+  const onBgMouseDown = (e: MouseEvent) => {
+    // 배경(빈 공간) 좌클릭에서만 시작 — 셀 클릭은 제외
+    if (e.button !== 0 || !(e.target as HTMLElement).dataset.gridbg) return;
+    const [sx, sy] = toContent(e.clientX, e.clientY);
+    setMarquee([sx, sy, sx, sy]);
+    if (!e.ctrlKey && !e.metaKey) clearSelection();
+
+    const onMove = (me: MouseEvent) => {
+      const [cx, cy] = toContent(me.clientX, me.clientY);
+      const m = marquee();
+      if (m) setMarquee([m[0], m[1], cx, cy]);
+    };
+    const onUp = () => {
+      document.removeEventListener("mousemove", onMove);
+      document.removeEventListener("mouseup", onUp);
+      commitMarquee();
+      setMarquee(null);
+    };
+    document.addEventListener("mousemove", onMove);
+    document.addEventListener("mouseup", onUp);
+  };
+
+  const commitMarquee = () => {
+    const m = marquee();
+    const l = layout();
+    const snap = snapshot();
+    if (!m || !l || !snap) return;
+    const [x1, y1, x2, y2] = [Math.min(m[0], m[2]), Math.min(m[1], m[3]), Math.max(m[0], m[2]), Math.max(m[1], m[3])];
+    // 너무 작은 드래그는 무시(클릭으로 간주)
+    if (x2 - x1 < 4 && y2 - y1 < 4) return;
+    const ids: number[] = [];
+    for (let i = 0; i < snap.count; i++) {
+      const bx = l.boxes[i * 4];
+      const by = l.boxes[i * 4 + 1];
+      const bw = l.boxes[i * 4 + 2];
+      const bh = l.boxes[i * 4 + 3];
+      // AABB 교차
+      if (bx < x2 && bx + bw > x1 && by < y2 && by + bh > y1) ids.push(snap.id(i));
+    }
+    setSelectionFromIds(ids);
+  };
+
+  const marqueeRect = createMemo(() => {
+    const m = marquee();
+    if (!m) return null;
+    return {
+      left: Math.min(m[0], m[2]),
+      top: Math.min(m[1], m[3]),
+      width: Math.abs(m[2] - m[0]),
+      height: Math.abs(m[3] - m[1]),
+    };
+  });
+
   return (
     <div
       ref={containerRef}
       onScroll={onScroll}
       onKeyDown={onKeyDown}
+      onMouseDown={onBgMouseDown}
       tabindex={0}
       class="relative min-h-0 flex-1 overflow-y-auto overflow-x-hidden px-2 py-2 outline-none"
     >
@@ -260,7 +328,24 @@ export const JustifiedGrid: Component = () => {
           </div>
         }
       >
-        <div class="relative" style={{ height: `${layout()?.totalHeight ?? 0}px` }}>
+        <div
+          class="relative"
+          data-gridbg="1"
+          style={{ height: `${layout()?.totalHeight ?? 0}px` }}
+        >
+          <Show when={marqueeRect()}>
+            {(r) => (
+              <div
+                class="pointer-events-none absolute z-10 border border-[var(--accent)] bg-[var(--accent-soft)]"
+                style={{
+                  left: `${r().left}px`,
+                  top: `${r().top}px`,
+                  width: `${r().width}px`,
+                  height: `${r().height}px`,
+                }}
+              />
+            )}
+          </Show>
           <For each={indices()}>
             {(i) => {
               const snap = snapshot()!;