fix: preserve Claude stdio MCP env

[imk1t]

Description

Preserve env values for self-defined stdio MCP servers when generating Claude Code .mcp.json.

Root cause: self-defined stdio MCP entries pass env into the shared adapter formatting path as a plain dictionary. The Copilot runtime-substitution path already handled that shape, but the legacy literal-resolution path used by Claude Code only handled registry-style environment variable lists, so the dictionary resolved to an empty object.

This keeps the fix scoped to that literal-resolution path and adds a Claude Code regression test proving that .mcp.json preserves the declared environment variable.

Fixes #1222

Type of change

• Bug fix
• New feature
• Documentation
• Maintenance / refactor

Testing

• Tested locally
• All existing tests pass
• Added tests for new functionality (if applicable)

Validation run:

uv run --extra dev pytest tests/unit/test_claude_mcp.py tests/unit/test_build_mcp_entry.py tests/test_codex_empty_string_and_defaults.py -q
uv run --project <repo> --extra dev apm install --target claude --no-policy
uv run --extra dev pytest tests/unit tests/test_console.py -x
uv run --extra dev ruff check src/ tests/
uv run --extra dev ruff format --check src/ tests/

The CLI smoke test used a generic self-defined stdio MCP entry with DEMO_ENV=demo-value and verified that the generated .mcp.json contains:

"env": {
  "DEMO_ENV": "demo-value"
}

[imk1t]

@microsoft-github-policy-service agree

[Copilot]

Pull request overview

Fixes a Claude Code-specific regression where self-defined stdio MCP servers lost their declared env when generating .mcp.json, by teaching the legacy (literal-resolution) env resolver to handle the self-defined env dict shape.

Changes:

• Extend _resolve_environment_variables to resolve env provided as a plain {NAME: value} dict when runtime env substitution is disabled (Claude Code path).
• Add a unit regression test asserting that .mcp.json preserves env for a self-defined stdio server.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
tests/unit/test_claude_mcp.py	Adds regression coverage for preserving env in Claude Code .mcp.json for self-defined stdio servers.
src/apm_cli/adapters/client/copilot.py	Updates legacy env-variable resolution to support dict-shaped env inputs used by self-defined stdio MCP entries.

[imk1t]

fixed