Summary

Workstream 1 landed canonical Windows fixes in:

• Process: fix Windows .cmd spawn EINVAL #29759
• fix(node-host): decode Windows exec output with active code page #30652

Remaining non-core spawn call sites still use mixed patterns and should be unified behind one tested Windows-safe strategy.

Scope

Unify Windows spawn behavior for these surfaces:

• src/memory/qmd-manager.ts
• extensions/acpx/src/runtime-internals/process.ts
• src/agents/sandbox/docker.ts
• src/acp/client.ts

Requirements

• One coherent strategy for .cmd/.bat handling.
• No duplicate wrapper patterns (shell:true + cmd /c double wrapping).
• Explicit argument-safety guarantees where command-line synthesis is required.
• Keep blast radius minimal; avoid unrelated refactors.

Test Gates (required)

Add targeted tests per touched surface to prove:

• Windows .cmd shims execute successfully.
• No regression for non-Windows paths.
• No command mangling with quoted args/spaces.
• No new injection surface from shell/wrapper behavior.

Acceptance Criteria

• Shared strategy documented in code comments in the helper/call site.
• All new tests pass locally and in CI.
• No broad behavior changes outside Windows spawn behavior.