v0.9.4: add real PTY dogfood for unified full-screen room

[spytensor]

Context

The unified room must be proven by real local user-case tests, not just unit tests. A user must be able to open the room, type into the composer, dispatch through host/role routing, and observe the public conversation/dashboard state without leaving the TUI.

Acceptance Criteria

• AC-1: Add a real PTY dogfood scenario for the non-default unified room entrypoint.
• AC-2: Scenario opens an initialized project, types a user message, dispatches it, and observes public conversation output/status without exiting to the old REPL.
• AC-3: Scenario covers explicit @role routing or documents why it is deferred.
• AC-4: Scenario covers a permission prompt path or documents why it is deferred.
• AC-5: Scenario verifies dashboard panels remain structured facts and do not become the authority for completion.
• AC-6: Only after this dogfood passes may a follow-up issue consider making the unified room the default bare cr path.

Required Evidence

• Dogfood command and output summary.
• PR body identifies real user cases covered and remaining gaps.

Dependencies

Depends on #305.

Tracker Update Required

Update #301 with this issue's PR/evidence row before completion.