feat: Add support for passing in environment variables to the WASM module

[kevinmingtarja]

Description

We do not yet have a way to pass in environment variables to the WASM module running the app. That is possible only for variables used in a Modus connection, where you could pass variables with the format MODUS_<CONNECTION NAME>_<KEY>, but within the app code users write, that is not accessible, as it's only accessible on the Runtime, and not passed down to the WASM module.

This PR improves this by passing in all environment variables prefixed with MODUS_ to the WASM module, so that the Modus app code can read it. Note that the MODUS_ prefix will be stripped before being passed in.

This also implies that if you have a connection secret MODUS_DGRAPH_API_KEY for example, then that would be passed to the WASM module as DGRAPH_API_KEY.

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[linear]

HYP-3258 add ability to read secrets (not only connection secrets) from a Modus app

[Copilot]

Pull Request Overview

This PR adds support for passing environment variables prefixed with "MODUS_" to the WASM module by stripping the prefix before forwarding them.

• Iterates through os.Environ() to extract MODUS_* environment variables
• Updates the WASM module configuration with the filtered environment variables

Comments suppressed due to low confidence (1)

runtime/wasmhost/wasmhost.go:140

• Consider adding unit tests to verify that environment variables prefixed with 'MODUS_' are correctly processed and stripped before being passed to the WASM module.

for _, env := range os.Environ() {