fix: resolve deprecation warning for apiKey value

[plumj-am]

Shown on startup:

Deprecation warning: registerProvider("commandcode") apiKey value "COMMANDCODE_API_KEY" is treated as a legacy environment variable reference. This will no longer be detected as an environment variable reference in a future release. Pass "$COMMANDCODE_API_KEY" instead.

Support for previous setup kept to avoid a breaking change.

[plumj-am]

@patlux bump :)

[patlux]

Validated this locally with pi 0.78.0.

• On main, COMMANDCODE_API_KEY=mock-key pi --no-extensions -e ./index.ts --list-models commandcode reproduces the deprecation warning.
• On this PR branch, the same command lists models without the warning.
• npm run typecheck passed.
• npm run test:stream passed.

The previous npm audit failure was a pre-existing baseline issue on main, not caused by this PR. It has since been fixed separately in #21, so I am updating this branch with latest main to re-run CI.

[patlux]

Thanks @plumj-am! I validated the fix locally with pi 0.78.0, updated the branch with latest main, and CI is green now. Appreciate the compatibility fix and the nudge 🙌

[patlux]

Shipped in pi-commandcode-provider@0.4.1 / GitHub release v0.4.1.