[TheGreatAxios]

Summary

• Exec resolves operator presence from stdin alone, so a piped stdout keeps permission prompts on stderr while stdout carries only command output
• Headless deny reasons name the missing channel (stdin is not a TTY); auto-deny rule names stay stable
• Ships Option A: stdin-present means an operator is present

Verification

• Critic follow-up (fb9af7a): pinned the undefined-stdio keeper cases — (undefined, undefined) headless+piped, (undefined, true) non-interactive+unpiped, (true, undefined) interactive+piped
• Synced docs to Option A: docs/PRODUCT.md exec section + operator-in-the-loop item, docs/ARCHITECTURE.md Exec Runner deltas (piped stdout with TTY stdin stays interactive, prompts on stderr)
• Ran bun install inside the worktree to pick up the origin/main oauth-core 0.2.0 pin; the earlier symlinked-node_modules load skew is gone
• bun test src/exec/runner.test.ts passes (32 pass, 0 fail)
• bun test src/permission passes (594 pass, 0 fail, 19 files)
• bun run typecheck clean; bun run lint clean (oxfmt + oxlint, 0 warnings)

Fixes CL-9002

[linear-code]

CL-9002

[TheGreatAxios]

Closing after the 0333 merge wave: rebase onto origin/main hit conflicts, and parent guidance is not to fight those. Reopen on a fresh branch if this still improves operator output without regression.