feat: CDI % configurável por conta + fix mocks de teste

- Adiciona campo cdi_percentage (default 100%) na tabela accounts
- Cálculo CDI aplica proporção: balance × (compound-1) × (pct/100)
- Frontend exibe input de % quando yield_type=cdi e badge mostra valor
- Corrige mocks de teste desatualizados (DeleteByMonth, isTax)
- Corrige ConfirmIncome para rejeitar tipo expense (ErrRecurringNotIncome)

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

apps/api/internal/migration/migration.go

@@ -50,6 +50,9 @@ var m013 string
 //go:embed sql/014_profiles.sql
 var m014 string
 
+//go:embed sql/015_accounts_cdi_percentage.sql
+var m015 string
+
 func Run(ctx context.Context, pool *pgxpool.Pool) error {
 	// Bootstrap: ensure schema_migrations table exists before checking versions.
 	if _, err := pool.Exec(ctx, `
@@ -61,7 +64,7 @@ func Run(ctx context.Context, pool *pgxpool.Pool) error {
 		return fmt.Errorf("bootstrap schema_migrations: %w", err)
 	}
 
-	migrations := []string{m001, m002, m003, m004, m005, m006, m007, m008, m009, m010, m011, m012, m013, m014}
+	migrations := []string{m001, m002, m003, m004, m005, m006, m007, m008, m009, m010, m011, m012, m013, m014, m015}
 	for i, sql := range migrations {
 		version := i + 1
 		var applied bool