Conste comes from the verb constar, which means 'to be on record' or 'to be evident'. In this context, it's used as an imperative, meaning "let it be known" or "just so you know."
Angela Aguilar uses this word to add emphasis and a touch of playful warning. She sings, "Que conste amor que ya te lo advertí," which translates to "Let it be known, my love, that I already warned you." It highlights her determination and confidence in winning over the person she desires.
Angela Aguilar's "Me Gustas Mucho" is such a fun, direct song about having a major crush and being absolutely determined to make it work! She's not shy about her feelings at all. From the very beginning, she declares, "Yo no he perdido la esperanza de tenerte entre mis brazos" [I haven't lost hope of having you in my arms], making it clear she's in it for the long haul.
What I love is her confidence! She states, "Lo que me gusta obtengo con toda seguridad" [What I like, I get with complete certainty]. It's a bold promise that she'll achieve her goal. She even gives a playful warning: "Que conste amor que ya te lo advertí que no descansaré hasta que seas mío" [Let it be known, my love, I already warned you that I won't rest until you're mine]. This song is all about that exciting, slightly obsessive feeling of knowing who you want and being sure you'll get them, no matter what!