Add prompt queue-ing, this such a basic feature needed, its always steering w...

Add prompt queue-ing, this such a basic feature needed, its always steering when i do subsequent prompts

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| Field | Value |
| --- | --- |
| App version | 1.1.5 |
| OS | Ubuntu 26.4.0 |
| Theme | Monospace |
| Path | /chat |
| Tenure | Day 1 |

Start with the /chat experience and determine how subsequent prompts are currently handled while one prompt is running. Define the queue behavior and completion criteria with the maintainers, then identify the relevant chat entry points and tests; done means prompts can be submitted consecutively and execute in order without steering the active task.

Written by the indexing model from the issue text.