No. In Starfinder, healing spells heal the undead in the same way as they heal regular living creatures.
Starfinder is based on Pathfinder. So let's first check the original Pathfinder rules first to see where it describes the way healing magic affects the undead.
One section which says that undead get hurt by healing magic is found in the Undead Trait which ...
Healing means the recovery of hit-points
While the above sentence is never spelled out verbatim, I want to make my case that when read with full context, the Player's Handbook is clear about it.
The first sentences in the section "Healing" in the PhB says:
Unless it results in death, damage isn't permanent. Even death is reversible through ...
RAW it's ambiguous.
The distinction between "healing" and "regaining hit points" is clearly related to getting hit for 0 damage and what that means.
On the one hand, this answer suggests that it is possible to hit for 0 damage, and therefore it should be possible to heal someone for 0 hit points. On the other hand, this answer suggests ...
For a being that possesses Rage, the minimum is 2.
A difficulty number is always from 2 to 10 (and usually between 3 and 9).1
Combining this with the gift specific rule, which states that the difficulty is the current rage, this solves the "1/0 Rage left" problem:
Mother's Touch is rolled against 2 or the current Rage, whichever is higher, as ...
When a feature prevents its target from the regaining of hit points, it does not prevent receiving healing.
No rule explicitly talks about a healing minimum, so we should assume that healing that features reduce to 0 still counts as receiving healing, similar to how receiving damage that features reduce to 0 counts as taking damage.
When a ...
You roll against their current Rage, not their permanent Rage.
On W20 Corebook p. 234, it says the following:
A difficulty number is always from 2 to 10 (and usually between 3 and 9).
The explicit text of the ability reads as follows, as you quoted it:
(difficulty is the target’s current Rage, or 5 for those with no Rage)
Since White Wolf uses natural ...
Healing is not the same as treating injuries
Healing in DnD 5e is the recovery of lost hit-points. Hit-points do not necessarily represent your physical condition, but rather
a combination of physical and mental durability, the will to live, and luck
So when you say
I'm made purely out of mechanical components so I should obviously be able to use any ...
The Made to Mend feature just doesn't make sense.
The Made to Mend feature states:
Made to Mend. When a creature casts the mending cantrip on you, you instead become stable if you are dying.
The mending cantrip has a casting time of 1 minute. It takes ten rounds of combat to cast mending. If you go down, and someone starts casting mending, you will either ...
Per the rules you linked, by default, you're a construct, and therefore, per the rules for most (all?) of the healing spells provided so far, you can't be magically healed. Mending only stabilizes, it doesn't heal, so that doesn't help.
Seems like the only way to be magically healed is if you selected the Alchemical Blood trait as one of your Maker's Marks:
Homebrew and Rules
I'll start by saying that any time you use homebrew you run into the large grey void of rules that may or may not work depending on what your homebrew says. In this case, just apply the idea that specific beats general and that your homebrew override rules as they are written. Now for the questions at hand.
How much does mending heal?
By the description you linked, Mending does nothing if you are stable.
From this discussion we see that
The Nimblewright from Waterdeep: Dragon Heist is a construct that has the repairable feature, which allows for mending to heal one hit point.
Your race does not have this feature, so as it is written it does not work for you. Of course you and your DM ...
Given that this is a homebrew race, it seems unlikely (and, in fact, completely impossible) that the game is actually designed to take it into account, and homebrew content frequently has issues with things that would come up in play-testing. As far as the content present only in the class, there is no way to answer this question; whoever created this race ...