Initial import: open-design source for helix-mind.ai distribution

This repository contains the open-design daemon CLI source code, built
and packaged at https://helix-mind.ai/cli/open-design/latest.tgz for use
by the HelixMind /design slash command.

Licenses: Apache-2.0 (root) + MIT (skills/*)

skills/hatch-pet/references/codex-pet-contract.md

@@ -0,0 +1,35 @@
+# Codex Pet Contract
+
+## Sprite Atlas
+
+- Format: PNG or WebP.
+- Dimensions: `1536x1872`.
+- Grid: 8 columns x 9 rows.
+- Cell: `192x208`.
+- Background: transparent.
+- Unused cells: fully transparent.
+
+The webview animation uses CSS background positions from the fixed row and column counts. Do not add labels, gutters, borders, grid lines, shadows outside the cell, or extra frames.
+
+## Local Custom Pet Package
+
+Place files under:
+
+```text
+${CODEX_HOME:-$HOME/.codex}/pets/<pet-name>/
+├── pet.json
+└── spritesheet.webp
+```
+
+Manifest shape:
+
+```json
+{
+  "id": "pet-name",
+  "displayName": "Pet Name",
+  "description": "One short sentence.",
+  "spritesheetPath": "spritesheet.webp"
+}
+```
+
+The app loads custom pets from the folder name under `${CODEX_HOME:-$HOME/.codex}/pets/`.