Environment variable naming convention for resources not documented

[maddymontaquila]

Bug Description

Aspire transforms resource names into environment variable prefixes using a specific convention, but this convention is not clearly documented. When a resource is named with hyphens (e.g., foundry-demo-proj), the resulting environment variable prefix is FOUNDRY_DEMO_PROJ (uppercased, hyphens replaced with underscores). Properties are appended as suffixes (e.g., _URI, _MODELNAME).

Current Behavior

There is no clear documentation explaining the resource name → environment variable transformation rules. Users must discover the naming convention by trial and error or by inspecting the Aspire dashboard.

Expected Behavior

The docs should include a section explaining:

1. Resource names are uppercased
2. Hyphens (-) are replaced with underscores (_)
3. Properties are appended as _{PROPERTY} (e.g., _URI, _MODELNAME, _CONNECTIONSTRING)
4. Connection strings use the format ConnectionStrings__{resource-name}
5. Examples showing the mapping, e.g.: resource "my-db" → env vars MY_DB_HOST, MY_DB_PORT, ConnectionStrings__my-db

Page URL

Could be added to the app model fundamentals or a dedicated "environment variables" reference page.

Additional Context

We spent significant debugging time because our Python app referenced PROJ_URI when the actual variable was FOUNDRY_DEMO_PROJ_URI (resource was named foundry-demo-proj). This is especially impactful for non-.NET service projects (Python, Node.js) where developers must manually read environment variables rather than using typed Aspire client integrations.