Show a live, plain-language account of agent progress, outcomes, and blockers #99

Agent runs currently show their work as folded groups of raw tool calls in the chat timeline. While a run is active, a folded group makes the channel feel like nothing is happening, and it is hard to audit what the agent did at a glance. Expanding the group does not fix this: a wall of raw commands is hard to follow.

Show a clear, live, plain-language account of the run instead: what the agent is doing now, the meaningful outcomes so far, and anything blocking it. Keep the full tool calls and results available as the audit trail beneath that account.

Acceptance

• While a run is active, the chat shows what the agent is doing now in plain language, without anyone having to expand a tool group.
• Meaningful outcomes, such as files changed, checks passed or failed, issues/PRs filed, and decisions made, read as short statements rather than as the commands that produced them.
• Blockers and failures stand out, including when the agent is waiting on a participant, a failing check, or missing access.
• Each statement links to the tool calls behind it. Raw commands, output, truncation, and exit/error state stay inspectable and are never replaced by the summary.
• The account survives reconnecting and reopening the channel, and it matches the durable run history.
• Dogfood: follow a real multi-step run without expanding any groups, then audit one of its claims from its linked tool calls.

Notes

• Build on live tool progress (Show live tool progress in the channel #54) rather than a second progress store. Show live tool progress in the channel #54 covers raw live output; this issue covers the participant-facing account of the run.
• Open question: where does the account come from? The agent could narrate it, a separate model could derive it from tool events, or both. Whatever produces it must not change what was actually run or hide anything.
• Related: Notify participants when an agent finishes #12 (attention for finished, failed, or waiting runs), Rename channels and keep rolling summaries #23 (rolling channel summaries).

Part of #98. Dogfooding core/QOL: #5. Product feedback from Nate.