feat(tahesab): show remaining-time estimate in sync progress modal

Estimate ETA from processed throughput for customer export and document sync.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/components/TahesabDocSyncProgress.vue

@@ -38,6 +38,7 @@
               <div class="cip-track__fill" :style="{ width: store.percent + '%' }" />
             </div>
             <div class="cip-percent">{{ store.percent }}٪</div>
+            <div v-if="etaLabel" class="cip-eta">{{ etaLabel }}</div>
             <div class="cip-current">
               <a-spin size="small" />
               <span class="cip-current__name">{{ store.state.current || '...' }}</span>
@@ -127,6 +128,7 @@
             </template>
             <template v-else>{{ store.state.processed }} از {{ store.state.total }}</template>
           </span>
+          <span v-if="store.active && etaLabel" class="cip-mini__eta">{{ etaLabel }}</span>
         </span>
         <span class="cip-mini__bar">
           <span class="cip-mini__bar-fill" :style="{ width: store.percent + '%' }" />
@@ -137,12 +139,87 @@
 </template>
 
 <script setup lang="ts">
-import { computed, onMounted } from 'vue'
+import { computed, onMounted, onUnmounted, ref, watch } from 'vue'
 import Icon from '@core/components/BaseIcon/src/Icon.vue'
 import { useTahesabDocSyncStore } from '@/store/tahesabDocSyncStore'
 
 const store = useTahesabDocSyncStore()
 
+const runStartedAt = ref<number | null>(null)
+const runStartProcessed = ref(0)
+const tick = ref(Date.now())
+let tickTimer: ReturnType<typeof setInterval> | null = null
+
+function formatEta(seconds: number): string {
+  if (!Number.isFinite(seconds) || seconds <= 0) return 'به‌زودی'
+  const rounded = Math.ceil(seconds)
+  if (rounded < 60) return `حدود ${rounded} ثانیه`
+  const mins = Math.ceil(rounded / 60)
+  if (mins < 60) return `حدود ${mins} دقیقه`
+  const hours = Math.floor(mins / 60)
+  const remMins = mins % 60
+  if (remMins === 0) return `حدود ${hours} ساعت`
+  return `حدود ${hours} ساعت و ${remMins} دقیقه`
+}
+
+function resetEtaClock() {
+  runStartedAt.value = Date.now()
+  runStartProcessed.value = store.state.processed
+}
+
+function startTick() {
+  if (tickTimer) return
+  tickTimer = setInterval(() => {
+    tick.value = Date.now()
+  }, 1000)
+}
+
+function stopTick() {
+  if (!tickTimer) return
+  clearInterval(tickTimer)
+  tickTimer = null
+}
+
+watch(
+  () => store.active,
+  (active) => {
+    if (active) {
+      resetEtaClock()
+      startTick()
+      return
+    }
+    runStartedAt.value = null
+    stopTick()
+  },
+  { immediate: true },
+)
+
+watch(
+  () => store.state.stage,
+  () => {
+    if (store.active) resetEtaClock()
+  },
+)
+
+const etaLabel = computed(() => {
+  void tick.value
+  if (!store.active) return ''
+
+  const { processed, total } = store.state
+  const remaining = Math.max(0, total - processed)
+  if (remaining <= 0) return 'در حال اتمام…'
+  if (!runStartedAt.value) return ''
+
+  const deltaProcessed = processed - runStartProcessed.value
+  const elapsedSec = (Date.now() - runStartedAt.value) / 1000
+  if (deltaProcessed < 2 || elapsedSec < 4) {
+    return 'در حال محاسبه زمان باقی‌مانده…'
+  }
+
+  const secPerItem = elapsedSec / deltaProcessed
+  return `تخمین باقی‌مانده: ${formatEta(secPerItem * remaining)}`
+})
+
 const stage = computed(() => store.stage)
 
 function outcomeMap() {
@@ -217,6 +294,10 @@ const ringStyle = computed(() => ({
 onMounted(() => {
   void store.hydrate()
 })
+
+onUnmounted(() => {
+  stopTick()
+})
 </script>
 
 <style scoped lang="less">
@@ -360,6 +441,15 @@ onMounted(() => {
   color: var(--admin-text-secondary);
 }
 
+.cip-eta {
+  align-self: flex-end;
+  margin-top: 4px;
+  font-size: 11px;
+  font-weight: 600;
+  color: var(--admin-text-muted);
+  text-align: right;
+}
+
 .cip-current {
   display: flex;
   align-items: center;
@@ -622,6 +712,13 @@ onMounted(() => {
     white-space: nowrap;
   }
 
+  &__eta {
+    font-size: 10px;
+    font-weight: 600;
+    color: var(--admin-text-muted);
+    white-space: nowrap;
+  }
+
   &__bar {
     position: absolute;
     left: 14px;