[FEATURE] Generate binary cryptarithms

[arnaud-m]

Is your feature request related to a problem? Please describe.
The generator enforces that letters are associated to distinct digits.
So, binary cryptarithms cannot be generated.

Describe the solution you'd like
Relax the constraint that letters are associated to distinct digits.

Provide usage examples

java -cp cryptator-1.0.1-SNAPSHOT-with-dependencies.jar cryptator.Crypgen --base 2 -v verbose --generate ADD --solver ADAPT words/alpha.txt

The generation model enforces that

ARITHM ([symbCount <= 2])

But, one want to discover that

java -cp cryptator-1.0.1-SNAPSHOT-with-dependencies.jar cryptator.Cryptator --base 2 "pi+pi=rho" 

pi+pi=rho  
[2025-07-14 16:37:31] [INFOS] Find cryptarithm solution #1 [OK]
 h| i| o| p| r|
 0| 0| 0| 1| 1|  
...