Phase 2: asset/shot feature parity, task actions, member management

Phase 2 of frontend_tasks.md - close feature gaps between domains:

- Asset user-assignment popover, ported from shot's EditableTaskStatus,
  wired through columns.ts and AssetBrowser.vue.
- Asset column-locking toggle: two-pane frozen-column layout ported
  into AssetsDataTable.vue (adapted for asset's page-scroll layout,
  which has no bounded-height container like shot's).
- Task table row-actions menu (View Details + Reassign only - no
  Delete/Edit, since no backend support exists for either).
- Real select-task/create-task behavior on asset and shot detail
  panels: clicking a task swaps in the actual TaskDetailPanel in
  place; "Add Task" opens a task-type picker that creates real tasks
  via the existing createAssetTask/createShotTask services.
- create-note/upload-reference/publish-version implemented via a
  task-picker that deep-links into TaskDetailPanel's Notes/
  Attachments/Submissions tabs (new initialTab prop), reusing the
  already-working task-level components instead of building three new
  bespoke forms. Also fixed shot's pre-existing dead "Add Note"/
  "Upload Reference" buttons the same way.
- Consolidated ProjectMembersManager.vue and ProjectMemberManagement.vue
  into one component, combining remove-confirmation and approved-user
  filtering with toast feedback and the shared Select/Dialog UI kit.
- Wired ProjectDetailView's "Manage Members" to navigate to the
  project's Settings > Team tab.

Also fixed a bug in this session's own new code: TaskBrowser.vue's
row-click handler is a no-op by design, so the new row-actions menu
needed to emit row-double-click (which actually opens the panel)
instead.

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

frontend/src/views/ProjectDetailView.vue

@@ -147,8 +147,9 @@ const manageTechnicalSpecs = () => {
 }
 
 const manageMembers = () => {
-  // TODO: Implement member management
-  console.log('Manage members')
+  if (projectId.value) {
+    router.push(`/projects/${projectId.value}/settings`)
+  }
 }
 
 const getStatusVariant = (status: string) => {