Robot simulation descriptions (URDF, SRDF, SDF)

Step 0, before installing anything: read this install prompt, summarize in a few lines what this build does and what installing it involves, then ask me to confirm before you proceed. Prerequisites: text-to-cad installed (the cad command). If cad is not found, install it outside a sandbox or with its permission with curl -fsSL https://texttocad.dev/install.sh | sh (on Windows PowerShell: irm https://www.texttocad.dev/install.ps1 | iex), then run cad doctor, which explains the installation. One server runs for the installation: the first run starts it, cad status lists its workers and documents, cad stop stops it. URDF, SRDF or SDF files to author or review, or the robot's dimensioned drawings, measured values or CAD data (spatial transforms are never guessed). Gazebo (gz) only if you want the optional gz sdf check. Install "Robot simulation descriptions (URDF, SRDF, SDF)" for me. Author and validate robot descriptions for ROS, MoveIt and Gazebo: a URDF for the robot's structure (links, joints, geometry, inertials, limits, transmissions), an SRDF beside it for MoveIt's planning semantics (planning groups, end effectors, group states, disabled collision pairs), and an SDF for Gazebo models and worlds (sensors, plugins, physics). Every file starts with a design ledger kept as a comment block, SI units throughout, spatial transforms never guessed, computed numbers never freehanded, and each change checked with cad urdf validate, cad srdf validate or cad sdf validate, then reviewed with a snapshot in the CAD Viewer, by @earthtojake, MIT-licensed. Repository: https://raw.githubusercontent.com/earthtojake/text-to-cad/1cfd73cbbf0be943e0ff7aa0c672f824935b98a7/skills/robot-simulation/SKILL.md (the skill is the whole skills/robot-simulation/ folder at that commit: SKILL.md, LICENSE, agents/openai.yaml, and its references/ subfolder with 20 reference files: guardrails.md, inertials.md, interoperability.md, meshes.md, sdf-authoring.md, sdf-checks.md, sdf-examples.md, sdf-frames.md, sdf-ledger.md, snapshots.md, srdf-authoring.md, srdf-checks.md, srdf-disabled-collisions.md, srdf-end-effectors.md, srdf-ledger.md, urdf-authoring.md, urdf-checks.md, urdf-four-bar.md, urdf-frames.md, urdf-ledger.md) Pinned version: install the code at commit 1cfd73cbbf0be943e0ff7aa0c672f824935b98a7 exactly (Skill Harbor tested this version). Do not substitute a newer version. If this commit is unreachable, stop and tell me. 1. Download SKILL.md and its helper files from the repository folder into a temporary folder. 2. Safety check: read SKILL.md, review it and its scripts for anything suspicious (unexpected network calls, shell commands, credential harvesting) and STOP on any red flag and tell me. Tell me in plain words what the skill does when used, which services it connects to, whether it reads or sends any personal information, and anything that seems unusual. Confirm from the file: the tool is the cad command (the old cadgen launcher is gone); installation is the texttocad.dev script, run outside a sandbox or with its permission, and cad doctor explains the installation; descriptions are authored as XML with a design ledger first, spatial transforms are never guessed, and each change is checked with cad urdf validate, cad srdf validate or cad sdf validate. Nothing is sent anywhere during installation itself beyond the announced download of the skill files; the install script above is a separate step, covered by the Step 0 confirmation, if cad still needs installing. 3. When I say yes, install it as a skill: copy SKILL.md and its helper files into the agent's skills directory, in a folder named "robot-simulation", keeping the references/ and agents/ subfolders as they are. 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. install text-to-cad if cad is missing (outside a sandbox or with its permission, then cad doctor); prepare the URDF, SRDF or SDF files to author or review, or the robot's dimensioned drawings, measured values or CAD data, and expect a design ledger to be established before any XML is written.). 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. Never print or paste a secret value.