#29366 nightly: static capability check skips agent-session-folders-v1 (added at runtime), unblocking every tip nightly

Leo: "we just need the nightlies bro"

Cause

#29145 added agent-session-folders-v1 to the app's capability list (plans/cmux-next/daemon-capabilities.json). cmux-tui advertises it only from identify_capabilities, inside if mux.serves_agent_session_start() with the other agent-session-start capabilities, so __daemon-capabilities (the bundled static manifest) never lists it. check-daemon-capabilities.sh --static-only skips those through its hand-kept runtime_only set, which lacked the new one. Every nightly build of a commit after #29145 fails in build-nightly-app:

check-daemon-capabilities: the bundled static capability manifest is missing agent-session-folders-v1

so no tip has reached the NEXT feed since; only re-runs of runs for commits before #29145 publish.

Change

• agent-session-folders-v1 joins runtime_only.
• tests/test_cmux_next_static_capability_runtime_only.py reads identify_capabilities in cmux-tui-core's server/capabilities.rs, resolves each capability it pushes to its string, and fails when one is on the app's list but not in runtime_only. Red without the script change (['agent-session-folders-v1'] != []), green with it. Registered in tests/test-execution.toml (linux-guard) and run in ci-guards' nightly step.

Risk: low. The runtime check of these capabilities stays in the daemon integration lane, as for the other agent-session-start ones.

Agent session: agent session

🤖 Generated with Claude Code

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Summary by cubic

Fixes nightly builds failing because the static capability check didn't know agent-session-folders-v1 is only added at runtime.

• Adds agent-session-folders-v1 to runtime_only in check-daemon-capabilities.sh so the static manifest check no longer reports it as missing.
• Adds a test that parses identify_capabilities in cmux-tui-core and fails when a runtime-added capability on the app's capability list isn't in runtime_only, and registers it in test-execution.toml and the ci-guards nightly step.