feat: replace Stripe Global Payouts with manual bank transfer system for France compliance

- Replace Stripe automatic payouts with manual admin-processed bank transfers
- Add banking information fields (IBAN, bank name, account holder) to User model
- Implement manual payout workflow: pending → approved → processing → completed
- Add comprehensive admin interface for payout review and processing
- Update Payout model with manual processing fields and workflow methods
- Add transfer reference tracking and rejection/failure handling
- Consolidate all migration fragments into clean "create" migrations
- Add comprehensive documentation for manual payout workflow
- Fix Event payout_status enum definition and database column issues

This addresses France's lack of Stripe Global Payouts support by implementing
a complete manual bank transfer workflow while maintaining audit trails and
proper admin controls.

🤖 Generated with [Claude Code](https://claude.ai/code)

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

app/models/event.rb

@@ -17,12 +17,12 @@ class Event < ApplicationRecord
   }, default: :draft
 
   enum :payout_status, {
-    not_requested: 0,
+    pending_request: 0,
     requested: 1,
     processing: 2,
     completed: 3,
     failed: 4
-  }, default: :not_requested
+  }, default: :pending_request
 
   # === Relations ===
   belongs_to :user