opencode plugin <name> crashes with 'fetch() proxy.url must be a non-empty string' when HTTP_PROXY is set

[KaysonSear]

Describe the bug

When attempting to install any plugin using the opencode plugin <name> command, it crashes immediately if the HTTP_PROXY or HTTPS_PROXY environment variables are set.

The error thrown is:
request to https://registry.npmjs.org/<name> failed, reason: fetch() proxy.url must be a non-empty string

Steps to reproduce

1. Export a valid proxy URL in the terminal (e.g., export HTTP_PROXY="http://127.0.0.1:7890" and export HTTPS_PROXY="http://127.0.0.1:7890").
2. Run opencode plugin diff (or any other plugin).
3. See error:

■  Could not install "diff"
■  request to https://registry.npmjs.org/diff failed, reason: fetch() proxy.url must be a non-empty string

Expected behavior

The opencode plugin command's internal fetch logic should correctly parse the proxy URL from the environment variables and route the request, or cleanly bypass it. It seems to be an issue with how Bun's fetch or the custom proxy agent parses the environment variable string.

Environment

• OS: Linux
• OpenCode Version: 1.14.18

[github-actions]

This issue might be a duplicate of existing issues. Please check:

• Plugin install fails with valid proxy env: fetch() proxy.url must be a non-empty string #21468: Plugin install fails with valid proxy env: fetch() proxy.url must be a non-empty string
• Plugin installation fails: "fetch() proxy.url must be a non-empty string" even with proxy disabled #21327: Plugin installation fails: "fetch() proxy.url must be a non-empty string" even with proxy disabled
• Plugin install via npm fails behind proxy with 'fetch() proxy.url must be a non-empty string' #21098: Plugin install via npm fails behind proxy with 'fetch() proxy.url must be a non-empty string'
• @npmcli/arborist in Bun runtime fails to resolve proxy env vars: proxy.url must be a non-empty string #21472: @npmcli/arborist in Bun runtime fails to resolve proxy env vars: proxy.url must be a non-empty string
• request to https://registry.npmjs.org/oh-my-openagent failed, reason: fetch() proxy.url must be a non-empty string #21175 (closed): request to https://registry.npmjs.org/oh-my-openagent failed, reason: fetch() proxy.url must be a non-empty string