Make Ctrl+P toggle sent agent messages too

[snimu]

What this does

Ctrl+P toggles agent-to-agent messages open and closed. Until now it only worked on messages the agent received — messages it sent stayed collapsed (they only opened together with the whole tool output via Ctrl+O). Now Ctrl+P expands and collapses both sent and received messages together.

Why

Sent and received messages are two halves of the same conversation. Having one key expand one half, and a different key (meant for tool output) expand the other, was confusing and inconsistent.

How it works

There was already a single "are agent messages expanded" switch behind Ctrl+P. The sent-message display just wasn't connected to it — it was wired to the tool-output switch instead. The fix connects the sent-message display to the same switch the received messages use, and disconnects it from the tool-output one. So:

• Ctrl+P opens and closes all agent messages, sent and received.
• Ctrl+O goes back to meaning tool output only.
• No new keybinding, no second switch to keep in sync.

Changes

• The sent-message part of the code cell display now reads the shared message-expansion switch (+32/−1 across four files).
• Tests covering the new toggle behavior (+47/−1).
• One changelog entry.

Lines changed: source +32/−1, tests +47/−1, changelog +1/−0.

Checks

• npm run check clean.
• 184 tests across the touched areas pass.

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Note

Low Risk
UI-only expansion toggle fix with no auth, data, or protocol changes. Covered by updated unit and regression tests.

Overview
Ctrl+P now expands and collapses sent agent messages along with received ones. Previously, sent messages in IPython cells only opened with tool output via Ctrl+O.

Sent-message rendering in IPythonCellComponent is switched from the tool-output expanded flag to a separate agentMessagesExpanded state, and that state is threaded through ToolExecutionComponent and chat expansion so both message directions share the same toggle.

^{Reviewed by Cursor Bugbot for commit 6046984. Bugbot is set up for automated code reviews on this repo. Configure here.}

Note

Make Ctrl+P toggle expansion of sent agent messages independently of tool output

• Adds agentMessagesExpanded as an independent state flag in IPythonCellComponent so sent agent messages can expand/collapse separately from tool output expansion.
• ToolExecutionComponent gains setAgentMessagesExpanded() to propagate the global agent message expansion state down to nested IPython cells.
• InteractiveMode.applyChatExpansion now calls setAgentMessagesExpanded() on all supporting children when Ctrl+P is pressed, using a new hasAgentMessagesExpansion type guard.
• Newly created tool components inherit the current agentMessagesExpanded setting at construction time.

^{Macroscope summarized 6046984.}