e2e: add agent console pseudo-terminal smoke coverage

[codeaholicguy]

Current coverage

The Ink agent console has no E2E launch or interaction coverage.

What is missing

• Compiled console startup under a real pseudo-terminal
• Initial header, agent list, preview, help, and footer rendering
• Terminal resize handling and key routing
• Clean quit behavior and timely process exit
• At least one fake-agent selection/message action

Risk ranking

Medium, rank 10: unit component tests do not catch broken Ink packaging, TTY assumptions, or process lifecycle integration.

Recommended E2E tests

• Spawn agent console under a pseudo-terminal, assert initial panes render, send the quit key, and require a clean timely exit.

Acceptance criteria

• The checklist test is merged under e2e/.
• The test is deterministic in CI, has bounded timeouts, and always cleans up its PTY and child process.
• A packaging/startup regression fails before interaction assertions.

Related audit findings

C1 and D6: console provider behavior should derive from the shared adapter/capability registry.