According to this, 辛からい means both spicy and salty. Where I live we
associate spicy with pepper, not salt.
Agreeing with what @siikamiika stated, it could be a misrepresentation of 辛い【つらい】, but considering the dictionary you used was an English one, "Salty", in this case, can also refer to an upset person, in English terms.
So this sentence, given by the reference you provided with the meaning "salty":
彼女は多くの辛い思いを経験してきた。She has gone through many difficulties.
Could refer to her "upset" state referring to her experiences, or if replaced with 辛い【つらい】, her "painful experiences".
However, I am not certain that "salty" (in terms of emotion) in English, can also be 辛い 【からい】 in Japanese. 辛い【つらい】 makes more sense.
Are there words for differentiating foods with too much salt than
foods with too much pepper?
There are phrases, but not specific words. However notice that salt (塩) is used along with 辛い.
Too much salt: 塩が辛い or おお塩辛い
Too much pepper: コショウを入れすぎた