[teamleaderleo]

Fixes a base red in the CI guard group (runs 41493448800, 41493705936). test_no_workflow_adds_a_single_size_linux_job failed with {'platform-prod-secrets.yml': (1, 0)} != {}, and "Validate fork runner routing" failed too.

platform-prod-secrets.yml (added by #32470, dispatch-only since #32479) pinned vars.LINUX_RUNNER || 'blacksmith-4vcpu-ubuntu-2404', which is one size. It now resolves its runner the same way cloud-vm-env-audit.yml, the other cmux-next-production job, does: forks get ubuntu-24.04; otherwise vars.LINUX_RUNNER, then fromJSON(vars.RUNNER_POOLS).linux_4. One line; no change to steps, secrets or permissions.

Checked locally at this head:

• tests/test_ci_linux_single_size.py and tests/test_ci_fork_runner_routing.py pass; both fail on base.
• The other python steps of the ci guard group were run as well. test_ci_fleet_rule_lints, test_ci_merge_main and test_supplychain_security fail identically on base in this checkout (a sparse checkout and local environment), so this change doesn't cause them.

Agent session: agent session

🤖 Generated with Claude Code

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Summary by cubic

Fixes the CI guard group reds by having platform-prod-secrets.yml resolve its runner from the Linux runner pool instead of pinning a single size. The job now reads runners the same way cloud-vm-env-audit.yml does: forks get ubuntu-24.04, otherwise vars.LINUX_RUNNER then fromJSON(vars.RUNNER_POOLS).linux_4. Steps, secrets, and permissions are unchanged.

^{Written for commit 9192f0e. Summary will update on new commits.}

[github-actions]

cmux status _{(one comment, edited in place; each line is updated by the job that owns it)}

Review 9192f0e: HQ feed card · gallery before/after runs · checks

App of this head (app.zip, kept 1 day)

gh workflow run reload-build.yml -R manaflow-ai/cmux --ref feat-cmux-next -f tag=pr32507 -f ref=lane/platform-prod-secrets-runner -f platform=macos -f backend_mode=local

Shipped in:

• cmux NEXT nightly 1.0.0-nightly.4150011005501 (fbf9260854)
• cmux NEXT nightly 1.0.0-nightly.4150109776501 (ae802cfe75)
• cmux NEXT nightly 1.0.0-nightly.4150231832001 (9b07402606)
• cmux NEXT nightly 1.0.0-nightly.4150393750701 (3772956684)
• cmux NEXT nightly 1.0.0-nightly.4150650437301 (bf2b39f9c1)
• cmux NEXT nightly 1.0.0-nightly.4150555402401 (40c38ac9ba)
• cmux NEXT nightly 1.0.0-nightly.4150738990701 (069f8c0811)

[teamleaderleo]

Review (subagent claude-opus-5-5 medium): SHIP at 9192f0e. Both target guards (single-size ratchet, fork runner routing) fail at base on this file and pass at head. The expression matches cloud-vm-env-audit.yml exactly. 17 related runner guards pass at head. Follow-ups: none