[Feature] Prototype SSH session bootstrap with a mock terminal client

[moakilodash]

Problem

There is no proof yet that the Textual app can be delivered over SSH cleanly. Terminal resize, disconnect events, and session isolation need validation.

Proposed Change

Build a minimal prototype that spawns an SSH session, starts a Textual app instance, and handles disconnect or terminal resize events. Keep the prototype isolated from the main app to avoid coupling or breaking changes.

Acceptance Criteria

• Prototype code is in a separate module/branch and does not break main app
• SSH client can connect, receive a terminal, and interact with the Textual app
• Terminal resize events are forwarded and handled correctly
• Disconnect events are handled cleanly (graceful shutdown)
• Limitations are documented honestly (e.g., auth assumptions, session isolation)
• Maintainers can use this to decide whether to continue or pivot

Related

Depends on (but not blocking): Issue #9 (Propose SSH architecture)
See ROADMAP.md Phase 4 - SSH Delivery

Contributor Lane: SSH Delivery Exploration (Issue 10/2)
Difficulty: Hard
Related Phase: Phase 4 - SSH Delivery