[Feature] Work-oriented view for delegated coding tasks (not pure chat)

[HCH-hash]

Summary

Present assignment of a card to a coding agent as a work session (ordered steps + diffs) rather than a generic back-and-forth chat UI.

Problem

Assigning a task to a coding agent currently re-uses the same chat surface as a conversational exchange. For delegated coding work this is less legible: the important artefacts are steps, tool calls, and file diffs, not a free-form message thread.

Proposed Direction

• Introduce a work-session / task-run view optimised for agent execution:
  • Ordered steps / plan
  • Tool calls rendered as actions (especially Edit/Write as diffs)
  • Clear status and outcome
• Keep the existing chat UI for true conversational triggers.
• Optionally surface the same underlying events in both views.

Scope

• Product behavior
• Frontend
• AI Agent event model (if a clearer “run vs chat” distinction helps)
• Documentation
• Other

Additional Context

• Directly improves legibility of “watching an agent work”.
• Aligns with the broader naming idea of distinguishing a “task run / work session” from a “chat”.

[pullfrog]

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