feat(spreadsheet): D 잇기 마무리 — 진짜 부품으로 createSpreadsheet · 2단계 찾기 · 메모 · 서식 붓 · 골라 붙여넣기 · 폭 맞춤 · 함수 도움말

- spreadsheet.ts — 가짜 부품 자리(parts) 걷고 A · B · C · E 직접 잇기 · 2단계는 spreadsheet_extras.ts 로
- spreadsheet_extras.ts(새) — 메모 풍선(마우스 올림) · Shift+F2 메모 편집 · 서식 붓 단추 · Ctrl+Shift+V 값만 · 서식만 · 수식만 · 도구 모음 뒤 초점 되돌림
- spreadsheet_find_panel.ts(새) — Ctrl+F · Shift+F5 찾기 · Ctrl+H 바꾸기 패널
- spreadsheet_editor.ts — C editorSlot(격자 뿌리 기준) → 층 안 좌표 맞춤(slotOf) · 함수 자동 완성(Tab) · 인자 도움말
- spreadsheet_keys.ts · spreadsheet_mouse.ts — 2단계 잇기 자리 · 열 경계 두 번 누르면 폭 자동 맞춤
- 시험 — 함수 도움말 자리 판정 추가(8 묶음)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01L6KXAabDTenEU7hrDQmCKY

A00_Common/spreadsheet/spreadsheet.css

@@ -109,3 +109,151 @@
   background: #24292f;
   color: #fff;
 }
+
+/* 2단계 잇기 — 서식 붓 · 찾기 패널 · 메모 · 골라 붙여넣기 */
+.ss-brush {
+  flex: none;
+  padding: 0 8px;
+  border: none;
+  border-right: 1px solid #d0d7de;
+  background: none;
+  font: inherit;
+  cursor: pointer;
+}
+
+.ss-brush.is-on {
+  background: #dafbe1;
+  box-shadow: inset 0 0 0 2px #217346;
+}
+
+.ss--painting .ss-grid-host {
+  cursor: copy;
+}
+
+.ss-find {
+  position: absolute;
+  top: 4px;
+  right: 16px;
+  z-index: 20;
+  display: flex;
+  flex-direction: column;
+  gap: 4px;
+  padding: 8px;
+  border: 1px solid #d0d7de;
+  border-radius: 6px;
+  background: #fff;
+  box-shadow: 0 4px 12px rgb(0 0 0 / 15%);
+}
+
+.ss-find[hidden],
+.ss-find__row[hidden],
+.ss-memo[hidden],
+.ss-pick[hidden],
+.spreadsheet-comment-balloon[hidden] {
+  display: none;
+}
+
+.ss-find__row {
+  display: flex;
+  align-items: center;
+  gap: 4px;
+}
+
+.ss-find__input {
+  width: 180px;
+  padding: 2px 6px;
+  border: 1px solid #d0d7de;
+  font: inherit;
+}
+
+.ss-find__btn {
+  padding: 2px 8px;
+  border: 1px solid #d0d7de;
+  border-radius: 4px;
+  background: #f6f8fa;
+  font: inherit;
+  cursor: pointer;
+}
+
+.ss-find__opt {
+  display: flex;
+  align-items: center;
+  gap: 2px;
+  font-size: 12px;
+}
+
+.ss-find__status {
+  font-size: 12px;
+  color: #57606a;
+}
+
+.ss-memo,
+.spreadsheet-comment-balloon {
+  position: absolute;
+  z-index: 15;
+  min-width: 140px;
+  max-width: 260px;
+  padding: 4px 6px;
+  border: 1px solid #bf8700;
+  background: #fff8c5;
+  font: inherit;
+  white-space: pre-wrap;
+  box-shadow: 0 2px 6px rgb(0 0 0 / 15%);
+}
+
+.ss-memo {
+  min-height: 60px;
+  resize: both;
+  outline: none;
+}
+
+.ss-pick {
+  position: absolute;
+  z-index: 20;
+  display: flex;
+  gap: 2px;
+  padding: 4px;
+  border: 1px solid #d0d7de;
+  background: #fff;
+  box-shadow: 0 4px 12px rgb(0 0 0 / 15%);
+}
+
+.ss-pick > button {
+  padding: 2px 8px;
+  border: 1px solid #d0d7de;
+  background: #f6f8fa;
+  font: inherit;
+  cursor: pointer;
+}
+
+/* 함수 자동 완성 · 인자 도움말 */
+.ss-hint {
+  position: absolute;
+  z-index: 6;
+  min-width: 200px;
+  max-width: 360px;
+  border: 1px solid #d0d7de;
+  background: #fff;
+  font-size: 12px;
+  box-shadow: 0 4px 12px rgb(0 0 0 / 15%);
+}
+
+.ss-hint[hidden] {
+  display: none;
+}
+
+.ss-hint__item,
+.ss-hint__help {
+  padding: 2px 6px;
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+}
+
+.ss-hint__item {
+  cursor: pointer;
+}
+
+.ss-hint__item.is-on {
+  background: #ddf4ff;
+}