Recognize Namespace SSH commands for warpification

[warp-agent-staging]

Description

Recognize Namespace devbox ssh <devbox-name> and nsc ssh [<instance-id>] commands as SSH-like commands so Warp routes interactive sessions through its existing SSH warpification path.

nsc ssh uses token-aware parsing to reject PTY-disabled sessions and trailing remote commands while accounting for its documented flag arities. Truthy --disable-pty=<bool> and -T=<bool> values disable warpification, while false values preserve interactive detection. Bare nsc ssh remains interactive because the CLI can prompt for an instance. devbox ssh remains regex-only because this change does not infer trailing-command semantics without a complete, documented flag-arity table.

The narrower nsc scratch ssh form is intentionally omitted.

Linked Issue

Ad hoc factory ticket cdc0fe86-82d7-4fbf-93af-5ad533f75feb; no GitHub issue.

• The linked issue is labeled ready-to-spec or ready-to-implement. Not applicable; there is no linked GitHub issue.
• Where appropriate, screenshots or a short video of the implementation are included below (especially for user-visible or UI changes). Not applicable; this parser-only change does not alter UI, and computer-use verification was declined.

Testing

• cargo nextest run -p warp -E 'test(terminal::ssh::util::tests)' (7 passed)

• ./script/format (passed)

• cargo clippy --workspace --all-targets --tests -- -D warnings (passed)

• cargo clippy -p warp --all-targets --tests -- -D warnings (passed)

• I have manually tested my changes locally with ./script/run. Not run; the change is covered by parser unit tests and computer-use verification was declined.

Agent Mode

• Warp Agent Mode - This PR was created via Warp's AI Agent Mode

CHANGELOG-IMPROVEMENT: Added SSH warpification support for Namespace devbox and cloud commands.