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>

start.sh

@@ -0,0 +1,12 @@
+#!/bin/bash
+
+# Start both frontend and backend concurrently
+trap 'kill 0' EXIT
+
+echo "Starting backend server..."
+cd server && npm run dev &
+
+echo "Starting frontend client..."
+cd client && npm run dev &
+
+wait