Seat 4-DOF arm joints so links, yokes, and servos read as one machine

[w1ne]

Why

The Oct 6 release-pack arm painted with air between the link tubes and the joint housings. The solids stopped short of each other; a ten-pair solvedModel ignore list hid the overlaps without making hardware.

What changed

Both cookbook sources now build the same seated chain.

• Pitch joints are joint.clevis with liftPivot: false. Each link tube starts inside its tongue. A parent collar, side spines, and cheek disks bridge the fork. Cheek daylight is 0.4 mm per side. The parent collar stops 0.35 mm short of the tongue disk.
• The hinge pin is the clevis pin, with dark steel caps proud of both ears. Yaw is a spigot in a bored collar (0.28 mm radial, about 0.4 mm axial).
• Servo bodies sit 0.2 mm above their pads. The side horn stops about 0.6 mm short of the pin cap.
• Positive pitch is about −Y, so the existing reach-cycle keys lift the arm instead of driving it through the pedestal.
• The collision-ignore list is gone.

Unchanged contract: param() before animationView, part names, mechanicalJoint intents, and on the release pack arm.revolute plus kinematic.checkStaticHold. No Studio viewer or lighting changes.

Evaluate

	Before	After
Release pack	mechanism=real, featureCount 97, 10 ignore pairs	mechanism=real, featureCount 165, no ignores, no diagnostics
Multi-dof snippet	box yokes plus the same ignore list	mechanism=real, featureCount 160, full mate-limit sweep, no ignores

Renders

White-background publish renders of 4dof-release-evidence-pack. The side view is yaw 0 so the camera looks along the pin axis. The elbow frame is the upper link, forearm, and the fork between them.

Before, the old cookbook on develop (rods stop short of the housings):

Before: release-pack iso, links stop short of the joints

After, full arm:

After: iso, tubes seated in the clevis hubs

After: side, looking along the hinge pins

After, elbow clevis. The dark pin runs through both ears and the forearm sits in the fork:

After: elbow clevis, pin through both ears

After: elbow joint, three-quarter

Deploy

Cookbooks live in this repo and ship with the Studio deploy from develop. No kernelCAD-server vendor pin.

Not merged. Waiting on CI, then ready for review. Merge waits for an explicit OK in chat.

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