This is my first playthrough and I can't decide between conjuror or warrior... I wanted a druid or cleric type who uses magic enhanced with melee combat, but the only melee weapons a conjurer can use seem to be staves, and bows require ammo which is a logistics nightmare in my eyes. I don't know if staves become valid ,melee weapons later on.
Does the conjurer ever get better at blending spellcasting with melee or should I just bite the bullet and go for warrior?

Staves are a perfectly valid choice. If you stand still with them you can actually block attacks similar to the Warrior's shield, and you can get ones with abilities like knockback and such which are useful. At a point you do get an unbreakable weapon that can't be dropped that'll pretty much serve as melee replacement to the staves. Ammo for the bow really isn't much of a problem after a bit, you can easily get more arrows than you need, and later you can get a crossbow which hits really hard and pierces enemies but fires slower making it easier on ammo.

If you're wanting to go pure melee though, that's tricky because only the Warrior is really built for melee. You can get the strong leather armor with healing enchantments and use Vampirism to heal as you deal damage, but Conjurer just doesn't really have the health, armor, or physical strength for prolonged melee engagement. Best way to melee as a Conjurer with a staff is to fight defensively, letting the staff block hits and retaliating between attacks, much like when playing Warrior with a shield. You can melee much better than a Wizard and get some good melee kills, that's for certain, but any melee combat you do as a Conjurer is best to be brief, aided by creatures or spells, or done with the intent to create space for your arrows or spells.

Edit: Double checked, the Halberd later in the game can indeed block attacks like the staves can if you're facing the enemy and standing still.