fix(agent-core): use portable NO_PROXY for MCP children

[weivwang]

Related Issue

Resolve #1931

Problem

See linked issue. Kimi Code appends both bare and bracketed IPv6 loopback entries to NO_PROXY before spawning stdio MCP servers. The bracketed form is required by Node's environment-proxy implementation, but Python httpx parses it as an invalid port and can terminate before the MCP handshake.

What changed

• Generate a portable child NO_PROXY value without [::1] for non-Node MCP launchers while retaining the bare ::1 entry.
• Detect known Node launchers, including their Windows executable forms, and retain [::1] so Node still bypasses proxies for IPv6 loopback.
• Preserve an explicit per-server [::1] override for wrapper commands whose runtime cannot be inferred, and keep wildcard semantics unchanged.
• Apply the same behavior to both agent-core engines and add regression coverage for portable, Node, explicit-override, inherited, and wildcard paths.
• Add a patch changeset for the shipped CLI behavior.

Validation:

• pnpm --filter @moonshot-ai/agent-core test (4137 passed)
• pnpm --filter @moonshot-ai/agent-core-v2 test (4957 passed)
• pnpm --filter @moonshot-ai/agent-core typecheck
• pnpm --filter @moonshot-ai/agent-core-v2 typecheck
• pnpm exec oxlint on all changed TypeScript files
• Live compatibility probes confirmed Python httpx accepts the portable form and rejects [::1], while Undici needs [::1] to bypass an IPv6 loopback proxy.

Checklist

• I have read the CONTRIBUTING document.
• I have linked a related issue, or explained the problem above.
• I have added tests that prove my feature works.
• Ran gen-changesets skill, or this PR needs no changeset.
• Ran gen-docs skill, or this PR needs no doc update.

[changeset-bot]

🦋 Changeset detected

Latest commit: 96fa8ce

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@moonshot-ai/kimi-code	Patch

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