Add shareable URL support for VM templates/prompts

Author: bbornsztein Channel: #general Link: https://discord.com/channels/1405685085923049482/1405686123908567141/1479517527913795595

Description

Users should be able to share custom VM templates/prompts with others via a simple URL link, similar to how ideas can be shared.

Requested URL formats

https://exe.dev/new?idea=taskyou-os

Or preferably:

https://exe.dev/new?prompt=https://github.com/taskyou/taskyou-os/launch.md

The system should allow Shelley (the agent) to handle fetching and executing the prompt from the provided URL.

Use case

Users are building custom VMs for friends and clients but currently have no way to easily hand them off. A shareable link would streamline the process of distributing VM templates.

Context

User is already able to share HTTP proxy access but needs a way to share pre-configured VM templates/prompts. A workaround has been suggested: users can construct prompts that instruct the agent to curl a script (e.g., from a GitHub gist), but a more formal solution with native URL parameter support would be cleaner.

There's also broader interest in supporting personal template libraries for commonly-used VM configurations.