Friendship Directionality

Solution 1:

Friendship, like partnership and handshakes, is bidirectional. If it's one-sided, it might be a wish or infatuation etc, but it isn't friendship.

The key to deriving a unidirectional concept from it lies in your third example: one party may affirm the friendship while the other doesn't.

All 4 of your examples carry this idea: A considers or asserts the friendship, while B is silent about it. The examples express the opinion of A about the friendship, and there is certainly scope for opinions to differ.

A can consider/call/etc B a friend without B reciprocating. A can even maintain that opinion if B repudiates the friendship. That is, even if the (bidirectional) friendship doesn't exist, the (unidirectional) opinion can be alive and well.