[ST-4.2] feat: Add soft delete to education.course_reviews

- Added deleted_at and deleted_by columns for soft delete functionality
- Created migration 002-add_course_reviews_soft_delete.sql
- Added indexes for efficient active reviews queries
- Updated DDL schema definition with new columns and comments
- Gap: GAP-010

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

ddl/schemas/education/migrations/002-add_course_reviews_soft_delete.sql

@@ -0,0 +1,26 @@
+-- =====================================================
+-- MIGRATION: Add soft delete to course_reviews
+-- =====================================================
+-- Task: ST-4.2
+-- Gap: GAP-010
+-- Created: 2026-02-03
+-- =====================================================
+
+-- Add soft delete columns
+ALTER TABLE education.course_reviews
+  ADD COLUMN IF NOT EXISTS deleted_at TIMESTAMPTZ,
+  ADD COLUMN IF NOT EXISTS deleted_by UUID REFERENCES auth.users(id);
+
+-- Create index for soft delete queries
+CREATE INDEX IF NOT EXISTS idx_course_reviews_deleted_at
+  ON education.course_reviews(deleted_at)
+  WHERE deleted_at IS NULL;
+
+-- Create composite index for active reviews queries
+CREATE INDEX IF NOT EXISTS idx_course_reviews_active
+  ON education.course_reviews(course_id, deleted_at)
+  WHERE deleted_at IS NULL;
+
+-- Comments
+COMMENT ON COLUMN education.course_reviews.deleted_at IS 'Soft delete timestamp - cuando se marcó como eliminado';
+COMMENT ON COLUMN education.course_reviews.deleted_by IS 'ID del usuario que marcó como eliminado';