Add AGENTS.md with Cursor Cloud development instructions

[mlsoldano-boop]

Summary

Adds AGENTS.md with development environment instructions for Cursor Cloud agents working on this repository.

What's included

• Project overview (backend Express server + vanilla frontend)
• How to install dependencies and run the dev server
• Key caveats: no build step, no test framework, server requires valid EyePop.ai credentials to start

Environment verification

Dependencies install successfully in both root and server/ directories. The frontend serves correctly on port 5173:

GuideDog frontend loaded

Update script

The VM startup update script runs:

npm install --prefix /workspace
npm install --prefix /workspace/server

Blocking: EyePop.ai credentials required

The Express server requires EYEPOP_SECRET_KEY and EYEPOP_POP_ID environment secrets to start. Without valid credentials, the server exits at startup with an authentication error. These must be added as Cursor Cloud secrets.

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