feat: Add manual response dialog and update debt status handling

- Introduced ManualResponseDialog component for user-initiated responses when AI analysis is unclear.
- Updated DebtTimeline to include AlertTriangle icon for debts requiring manual review.
- Enhanced supabase functions to handle new debt status 'requires_manual_review' and message type 'manual_response'.
- Implemented email variable processing utilities to support dynamic email content generation.
- Created tests for email variable extraction and replacement functions.
- Updated database schema to accommodate new statuses and message types, including relevant constraints and indexes.
- Adjusted negotiation and email sending logic to ensure proper handling of manual responses and variable replacements.

supabase/migrations/20250608050000_add_manual_review_status.sql

@@ -0,0 +1,49 @@
+-- Add manual review status and message type
+-- This migration adds support for manual review when AI can't determine creditor intent
+
+-- Update debts table status constraint to include requires_manual_review
+ALTER TABLE debts 
+DROP CONSTRAINT IF EXISTS debts_status_check;
+
+ALTER TABLE debts 
+ADD CONSTRAINT debts_status_check 
+CHECK (status IN (
+  'received', 
+  'negotiating', 
+  'approved', 
+  'sent', 
+  'awaiting_response',
+  'counter_negotiating',
+  'requires_manual_review',
+  'accepted', 
+  'rejected',
+  'settled', 
+  'failed', 
+  'opted_out'
+));
+
+-- Update conversation_messages table message_type constraint to include manual_response
+ALTER TABLE conversation_messages 
+DROP CONSTRAINT IF EXISTS conversation_messages_message_type_check;
+
+ALTER TABLE conversation_messages 
+ADD CONSTRAINT conversation_messages_message_type_check 
+CHECK (message_type IN (
+  'initial_debt', 
+  'negotiation_sent', 
+  'response_received', 
+  'counter_offer', 
+  'acceptance', 
+  'rejection',
+  'manual_response'
+));
+
+-- Add comments for documentation
+COMMENT ON CONSTRAINT debts_status_check ON debts IS 'Valid debt statuses including manual review for unclear AI responses';
+COMMENT ON CONSTRAINT conversation_messages_message_type_check ON conversation_messages IS 'Valid message types including manual responses from users';
+
+-- Add index for manual review status for performance
+CREATE INDEX IF NOT EXISTS idx_debts_manual_review ON debts(status) WHERE status = 'requires_manual_review';
+
+-- Update RLS policies to handle manual responses (already covered by existing policies)
+-- No additional RLS changes needed as existing policies cover manual_response message type