URDF robot description authoring and validation

Prerequisites: Python with pip; the skill's requirements.txt installed with the active interpreter; Chromium via Playwright for snapshots; existing dimensioned drawings, measured values or CAD data for the robot (never guess spatial transforms) Install "URDF robot description authoring and validation" for me. Treat URDF as constrained kinematic modeling: author the .urdf directly as the source of truth, open with a design ledger (frames, joints, geometry, units, assumptions), get joint-origin/link-frame/axis semantics exactly right, compute inertia tensors and derived numbers (never freehand), validate every file with cadgen urdf validate (structure, topology, joint semantics, geometry, meshes, materials, inertial physics), snapshot robots to PNG for a joint-by-joint viewer sweep, and hand completed work to $cad-viewer when installed. Repository: https://github.com/earthtojake/text-to-cad/blob/main/skills/urdf/SKILL.md 1. Fetch the SKILL.md file (and any helper files) from the repository path into a temporary folder and summarize what it does in one or two sentences. 2. Safety check: review the SKILL.md and scripts for anything suspicious (unexpected network calls, shell commands, credential harvesting). This repo should contain zero secrets in code, credentials only via the secure vault, allowed hosts declared in the SKILL.md. Verify that holds here; STOP on any red flag and tell me. 3. Install it as a skill: copy SKILL.md and its helper files into the agent's skills directory, in a folder named "urdf". 4. Verify with no network calls: frontmatter valid, files in place. 5. Report what was installed, where, and what I still need to do myself (e.g. pip install the skill's requirements.txt, install Chromium via Playwright, hydrate Git LFS mesh pointers, prepare the robot's dimensions and assumptions ledger). GitHub is optional: if I have a GitHub account or the gh CLI, you may use it; otherwise public access is fine. Never require it unless it's in the prerequisites above. Rules: don't touch anything outside the temp folder and the install target. If anything looks off, stop and ask me.