(Again, this is outside of the context of a specific game.)

I've asked a few questions of this sort before, but there's one more thing I need to ask: What weapon type is best for healing? Which weapon type has the biggest variety of healing techniques, and which one has the strongest healing?

scalpel?
this topic makes no sense

The healing rod in Final Fantasy XII gives a regen buff to whoever you hit.

There are some unique weapons in Pillars of Eternity that will restore a wielder's endurance every time a foe is damaged.

In the Trails series, a few characters (who use projectile weapons like bows and guns) can fire alternative ammo that heals allies, but that is tied to the character's crafts (skill) rather than specific weapons.

if this is the last question that means your indie game is finished?

The Healing Staff actually has a rather long history in the Final Fantasy series:
FF1: Use as an item during battle to cast Heal, which restores a small amount of HP to the party. (Actually very useful in classic FF1 (PSX and earlier) due to the scarcity of healing resources.)
FF2: Heals whoever gets hit. (Note that the fan translation mistranslated this weapon's name.)
FF4: Use as an item to slightly heal the party. Note that this tends to be more of a mid-game item that is not worth using later on. (In 2D versions, it's a nice option for Cecil in the magnetic cave, but in 3D versions he can't equip it, and items can't be used without equipping them in FF4.)
FF5: Does nothing to whatever it hits, but additionally has a 100% chance of casting Cura.
FF6: Heals whoever gets hit, and is actually really powerful.
FF9: I believe this weapon exists, and it teaches a passive ability that makes the character's normal attack heal (but unfortunately is only available to characters with weak physical attacks).

I think rods are pretty much the only thing I've seen in Western RPGs? I could see a dart gun working in a more modern setting.

Baldur's Gate 1 has a cursed sword that reverse drains whatever it hits. Just add some regeneration on the wielder and you have a nice healing method! (Mod idea: Give this weapon health regen to its user, while leaving its other properties unchanged.)

Icewind Dale 2 has a pair of swords (one being the other's Heart of Fury replacement) that heal instead of doing damage.

Staves, wands, tomes, bibles, scrolls.

If the healer's magic comes from within, any accessory they use to enhance their magic can be considered a magic. Ankhs, antiques, jewels, rings, rosaries, gloves, bracelets, necklace, earrings, and other accessories. Then they can wield another weapon.

Ragnarok Online does this with healing monks or champion classes where they can still use fists, knuckle weapons, maces, and chains.

Well, the beast weapon for healing would, to my mind, be the “Shih Tzu on a pole +3 ice damage”. This is because the dog is hypoallergenic, and the ice provided numbing effects.
You could also have a “pig on a stick”, that is a porcine “ham”mer, and bacon is widely renowned for being able to resurrect the dead on Sunday morning after a heavy session.
What about a throwable? Maybe “jar of leeches”?
And perhaps a mace like weapon, “the flayed of dried skin”, or “the collossal foot file”. I was actually looking for the medical name, however this one came up in the search and is real!
https://www.amazon.com/Colossal-Scrubber-Pedicure-Professional-Stainless/dp/B08SWV1X6D/ref=zg_bs_11063611_8?_encoding=UTF8&psc=1&refRID=E1X6BQQ9BNW6MGN77H27

Ahh.. The classic healing punch in the face. ( or healing touch)

Actually, in the game I'm playing right now, SaGa Frontier 2, there is a weapon called the Beast Lance. It works rather well as a weapon, but it also provides Beast anima, which alone allows the character to cast Regenerate (assuming that art has been learned, but fortunately, it's not too hard to learn).

(Beast is also used for some other spells, including Reviva and Soul Hymn, but those spells need other anima types (Flame for both, Tone for Soul Hymn), and Soul Hymn is not easy to learn.)

(Also, "Beast" was indeed a typo in the topic title.)

I don't know if I'd call it the best, but the most memorable was definitely the healing gun that my healer, Mari, had in the Flash game Cristal Story II. It didn't really made that much sense, even in context, but it was fun. :D

*Puts a vampiric bludgeon back on the weapons rack*

Similar to this, in Bravely Default there are Equips that allow you to cast some spell if you use it as an item. They must be equipped by one of the characters, of course. (For example during a bit I used to don a bow that allows the character to cast Haste)
So, it happens that there is a fairly decent shield with the Cura spell. (I think it is Cura, might be a variation)

I always felt it was a pity that my favored strategies didn't happen to include any of the classes that favor shields, and that they usually called for at least one member to dual equip a high MATK+MDEF job and White Mage (or even Red Mage), making the shield less relevant by comparison.

Speaking of shields with healing magic, there are other examples:
* In Dragon Quest 2, there's the Shield of Strength, which casts Healmore (Midheal in later translations) on the user (only) for free, which is incredibly handy (to the point where it's even worth getting one for the princess, even though she can't equip it). This item would appear in every later game in the series I've played, though it tends to be less useful due to other free healing options (sage's stone, staff of healing, hustle dance) being available.
* In Wizardry 2 (Knight of Diamonds), KOD's Shield casts a healing spell, usable both in and out of battle, with no break chance.
* Similarly, Phantasy Star 3's Force Shield will restore 50 HP for free both in and out of battle. Then again, there's the Force Claw, a weapon that casts Rever for free when used; powerful healing, but unreliable and only works on dead targets (though you can use the Royal Vest to get a dead character to use it on, as it casts NASAK with 100% success rate).
* Life Corsage in Paladin's Quest. Don't know whether it counts as a weapon or a shield (it's held in the hand), but it fully heals the user. In Lennus 2, this item's effect has changed; it restores 300 HP to the entire party, and even revives dead characters. (Note that characters end up with a few thousand HP by end game in Lennus 2.)