#33063 cmux-api: forward the Cloud login copy switch to the platform

The Mac app reads a remote off switch before it copies a person's own Claude login to their own Cloud machine (Leo, 2026-11-02: "A remote off switch, so if Anthropic objects we turn it off for everyone within minutes and fall back to the one-click sign-in."). The route, GET /v1/cloud/harness-login-copy -> {enabled, ttlSeconds}, lives in the platform Worker (manaflow-ai/cmux-platform#587). Clients enter at cmux-api, whose forwarder sends only the platform paths it lists, so this adds the path to CLOUD_PATHS in platform-forward.ts and to the forwarder test's forwarded requests.

With PLATFORM_SURFACES unset (local) nothing changes; with cloud on (development, staging, production) the path goes to the platform like the other machine routes.

Test

vitest run test/platform-forward.test.ts on the fleet: 10 passed.

Agent session: agent session

🤖 Generated with Claude Code

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Summary by cubic

Forwards the Cloud login copy switch to the platform so the Mac app can read the remote off switch before copying a user's own Claude login to their Cloud machine.

• Adds /v1/cloud/harness-login-copy to the forwarder's CLOUD_PATHS and to the forwarder test's forwarded requests.
• With PLATFORM_SURFACES unset (local), nothing changes; with the cloud surface on, the route reaches the platform Worker alongside the machine routes.