Campaign assignments, ownership-based editing, and role-scoped data

- Add campaign_assignments table for user-to-campaign mapping
- Superadmin/managers can assign users to campaigns; visibility filtered by assignment/ownership
- Managers can only manage (tracks, assignments) on campaigns they created
- Budget controlled by superadmin only, with proper modal UI for editing
- Ownership-based editing for campaigns, projects, comments (creators can edit their own)
- Role-scoped dashboard and finance data (managers see only their campaigns' data)
- Manager's budget derived from sum of their campaign budgets set by superadmin
- Hide UI features users cannot use (principle of least privilege across all pages)
- Fix profile completion prompt persisting after saving (login response now includes profileComplete)
- Add post detail modal in campaign detail with thumbnails, publication links, and metadata
- Add comment inline editing for comment authors
- Move financial summary cards below filters on Campaigns page

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

client/src/pages/Projects.jsx

@@ -2,6 +2,7 @@ import { useState, useEffect, useContext } from 'react'
 import { Plus, Search, FolderKanban } from 'lucide-react'
 import { AppContext } from '../App'
 import { api } from '../utils/api'
+import { useAuth } from '../contexts/AuthContext'
 import ProjectCard from '../components/ProjectCard'
 import Modal from '../components/Modal'
 
@@ -12,6 +13,7 @@ const EMPTY_PROJECT = {
 
 export default function Projects() {
   const { teamMembers, brands } = useContext(AppContext)
+  const { permissions } = useAuth()
   const [projects, setProjects] = useState([])
   const [loading, setLoading] = useState(true)
   const [showModal, setShowModal] = useState(false)
@@ -81,13 +83,15 @@ export default function Projects() {
           />
         </div>
 
-        <button
-          onClick={() => setShowModal(true)}
-          className="flex items-center gap-2 px-4 py-2 bg-brand-primary text-white rounded-lg text-sm font-medium hover:bg-brand-primary-light shadow-sm ml-auto"
-        >
-          <Plus className="w-4 h-4" />
-          New Project
-        </button>
+        {permissions?.canCreateProjects && (
+          <button
+            onClick={() => setShowModal(true)}
+            className="flex items-center gap-2 px-4 py-2 bg-brand-primary text-white rounded-lg text-sm font-medium hover:bg-brand-primary-light shadow-sm ml-auto"
+          >
+            <Plus className="w-4 h-4" />
+            New Project
+          </button>
+        )}
       </div>
 
       {/* Project grid */}