feat(remote-development): add brokered SSH sandbox access

[mscolnick]

Adds opt-in brokered SSH access for exclusive editor sandboxes, including an authenticated WebSocket relay, short-lived user keys, pinned host keys, periodic reauthorization, and lifecycle leases.

• Adds CLI commands for interactive SSH and VS Code Remote-SSH, plus session capability and availability APIs.
• Adds a hardened rootless OpenSSH development image and web guidance for eligible sessions.
• Adds connector support for Docker, Podman, Kubernetes, and Modal while keeping provider endpoints private.
• Rejects unsafe container configurations, including public bind hosts and remote Docker or Podman daemons.
• Preserves user-managed SSH configuration through locked updates and symlink-safe atomic writes.

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1 Skipped Deployment

Project	Deployment	Actions	Updated (UTC)
marimohub-docs	Skipped		Aug 31, 2026 3:01pm

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Pull request overview

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