Move zoom control into the status bar, right end

Was a floating pill pinned to the bottom-right corner of the canvas
(SheetCanvas.vue's .zoom-ctl); now lives as the last element of the
status bar (StatusBar.vue), after a thin divider, in the same combined
bottom row as the sheet tabs. Same three actions (−, current % as a
button that resets to 100%, +), same store.activeZoom/setZoom.
Ctrl/Cmd+scroll-to-zoom on the canvas is unaffected.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/components/SheetCanvas.vue

@@ -109,13 +109,6 @@ function selectObj(id: string) {
       </div>
     </div>
 
-    <div class="zoom-ctl">
-      <button @click="setZoom(zoom - 0.1)">−</button>
-      <span>{{ Math.round(zoom * 100) }}%</span>
-      <button @click="setZoom(zoom + 0.1)">＋</button>
-      <button class="fit" @click="setZoom(1)">100%</button>
-    </div>
-
     <div v-if="dropActive" class="drop">Datei ablegen (.json .csv .xlsx)</div>
   </div>
 </template>
@@ -170,34 +163,6 @@ function selectObj(id: string) {
   height: 62px;
   opacity: 0.9;
 }
-.zoom-ctl {
-  position: absolute;
-  right: 16px;
-  bottom: 16px;
-  display: inline-flex;
-  align-items: center;
-  gap: 6px;
-  padding: 4px 8px;
-  background: var(--surface);
-  border: 1px solid var(--border);
-  border-radius: 999px;
-  box-shadow: var(--shadow);
-  font-size: 12px;
-  font-variant-numeric: tabular-nums;
-  z-index: 15;
-}
-.zoom-ctl button {
-  border: 1px solid var(--border);
-  background: var(--surface);
-  border-radius: 6px;
-  width: 22px;
-  height: 22px;
-  cursor: pointer;
-}
-.zoom-ctl button.fit {
-  width: auto;
-  padding: 0 8px;
-}
 .drop {
   position: absolute;
   right: 24px;