The description of Sneak Attack lists the requirements to take effect as a
If you hit a creature that has the footing condition (page 620)
with an agile melee weapon or finesse, an agile or finesse without weapons
attack, or remotely armed attack
And the Telekenetic Projectile spell requires you to
Make a ranged attack against the target
This is not a range armed attack as required by Sneak Attack. Plus, it's not a spell attack like Magical Trickster asks
When you succeed in a spell attack, cast an AC against a flat-footed enemy.
and the spell deals damage
and so will not even benefit from Sneak Attack if you have this feat.
From the General Rules section on page 446
The attack jets take various forms and are often very variable
depending on the weapon you are using for the attack, but there are three
main types: melee attack rolls, ranged attack rolls, and spell attacks
Which seems to indicate that you can not really have an untyped "remote attack" stream. It is therefore logical to assume that the reference to "ranged attack" in the Telekenetic Projectile entry refers to a "ranged attack" because the damage component benefits from your spell casting modifier. If this is the case (and I would decide that way as GM), then you can enjoy Sneak Attack. if you had the feat of Magical Trickster.