feat: bulk delete, team dispatch, calendar views, timeline colors

- Multi-select bulk delete in all 5 list views (Artefacts, Posts, Tasks,
  Issues, Assets) with cascade deletes and confirmation modals
- Team-based issue dispatch: team picker on public issue form, team filter
  on Issues page, copy public link from Team page and Issues header,
  team assignment in IssueDetailPanel
- Month/Week toggle on PostCalendar and TaskCalendarView
- Month/Week/Day zoom on project and campaign timelines (InteractiveTimeline)
  and ProjectDetail GanttView, with Month as default
- Custom timeline bar colors: clickable color dot with 12-color palette
  popover on project, campaign, and task timeline bars
- Artefacts default view changed to list
- BulkSelectBar reusable component
- i18n keys for all new features (en + ar)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

client/src/pages/Campaigns.jsx

@@ -50,7 +50,7 @@ export default function Campaigns() {
   const loadCampaigns = async () => {
     try {
       const res = await api.get('/campaigns')
-      setCampaigns(res.data || res || [])
+      setCampaigns(Array.isArray(res) ? res : [])
     } catch (err) {
       console.error('Failed to load campaigns:', err)
     } finally {
@@ -202,6 +202,7 @@ export default function Campaigns() {
           status: campaign.status,
           assigneeName: campaign.brandName || campaign.brand_name,
           tags: campaign.platforms || [],
+          color: campaign.color,
         })}
         onDateChange={async (campaignId, { startDate, endDate }) => {
           try {
@@ -212,6 +213,15 @@ export default function Campaigns() {
             loadCampaigns()
           }
         }}
+        onColorChange={async (campaignId, color) => {
+          try {
+            await api.patch(`/campaigns/${campaignId}`, { color: color || '' })
+          } catch (err) {
+            console.error('Color update failed:', err)
+          } finally {
+            loadCampaigns()
+          }
+        }}
         onItemClick={(campaign) => {
           navigate(`/campaigns/${campaign._id || campaign.id}`)
         }}