Render cloud task history from typed session events

[osortega]

Renders Copilot Cloud Tasks history through the same session-event pipeline the CLI uses, so tool cards, edits, bash terminal output, search results, subagents and MCP results all look identical across providers.

Changes

• New shared renderer at extensions/copilot/src/extension/chatSessions/common/sessionEventRenderer.ts. Owns the per-turn state (ResponseEventRenderContext) and dispatches assistant.message / assistant.message_delta / tool.execution_* / subagent.* / session.error / abort events into ChatResponseTurn2 parts.
• copilotCLITools.buildChatHistoryFromEvents now delegates the response-part rendering to the shared helper. Turn-boundary logic (user.message handling, mode instructions, model id tracking) stays in the CLI builder. Net change in copilotCLITools.ts is +25 / -135 lines — pure extraction, no behavior change.
• copilotCloudSessionContentBuilder.buildTaskResponseTurn calls the shared renderer too, with a small remap from custom_agent.* → subagent.* (both follow the same CMC OpenAPI schema; only the names differ).
• Match github.com/github/github-ui presentation for cloud tasks: the cloud agent emits intermediate assistant.message events that echo tool input/output (raw diffs, file dumps). Keep only the last top-level assistant.message with non-empty content; tool rows render the rest.
• Plumb ILogService through ChatSessionContentBuilder so the shared renderer can log MCP block conversion errors.

Notes

• This depends on the updated @vscode/copilot-api package that ships the discriminated AgentTaskSessionEvent union. Until that's bumped, expect compile errors against event.data in the cloud builder — those will go away with the next package update.
• CLI behavior is byte-identical to main aside from the shared helper indirection.

Test plan

• Open an existing Copilot Cloud task session in chat and confirm the history matches the github.com/.../tasks/* view: short tool rows, no raw diff dumps in assistant text, the final summary message at the bottom.
• Open a Copilot CLI session and confirm tool rendering, edit diffs, terminal output, subagent groups and MCP results all still look the same.

[Copilot]

Pull request overview

Extracts response-event-to-ChatResponseTurn2 rendering out of the CLI history builder into a shared module so the Copilot Cloud Tasks history can render through the same pipeline (tool cards, edit diffs, terminal output, subagents, MCP results). The CLI builder still owns turn boundaries / request-turn construction and now delegates the response side to the shared helper; the cloud task builder swaps its stub state/model/branch summary for the same typed-event rendering, with a small custom_agent.* → subagent.* name remap, last-message-only filtering for cloud, and ILogService plumbed in to log MCP conversion failures. Also bumps @vscode/copilot-api to ^0.4.1 to pick up the discriminated AgentTaskSessionEvent union.

Changes:

• Introduce shared sessionEventRenderer.ts exposing ResponseEventRenderContext, appendResponsePartsForEvent, flushPendingAssistantMessage, and createResponseEventRenderContext.
• Refactor buildChatHistoryFromEvents to delegate response-part rendering to the shared helper; rewrite buildTaskResponseTurn to drive typed events through it with a custom_agent.* → subagent.* remap and last-final-message filter.
• Inject ILogService into ChatSessionContentBuilder (and update all construction sites + tests); bump @vscode/copilot-api from ^0.4.0 to ^0.4.1 across all manifests/lockfiles.

Show a summary per file

File	Description
extensions/copilot/src/extension/chatSessions/common/sessionEventRenderer.ts	New shared renderer for response-side session events.
extensions/copilot/src/extension/chatSessions/copilotcli/common/copilotCLITools.ts	Delegate response-part rendering to the shared renderer; keep turn-boundary handling.
extensions/copilot/src/extension/chatSessions/vscode-node/copilotCloudSessionContentBuilder.ts	Replace stub task summary with event-driven rendering via the shared helper; add custom_agent.* remap and inject ILogService.
extensions/copilot/src/extension/chatSessions/vscode-node/copilotCloudSessionsProvider.ts	Pass this.logService to all ChatSessionContentBuilder constructions.
extensions/copilot/src/extension/chatSessions/vscode-node/test/copilotCloudSessionsProvider.spec.ts	Update test to pass TestLogService to the builder.
package.json / package-lock.json	Bump @vscode/copilot-api to ^0.4.1.
remote/package.json / remote/package-lock.json	Bump @vscode/copilot-api to ^0.4.1.
extensions/copilot/package.json / package-lock.json	Bump @vscode/copilot-api to ^0.4.1.
extensions/copilot/chat-lib/package.json / package-lock.json	Bump @vscode/copilot-api to ^0.4.1.

Copilot's findings

Files not reviewed (3)

• extensions/copilot/chat-lib/package-lock.json: Language not supported
• extensions/copilot/package-lock.json: Language not supported
• remote/package-lock.json: Language not supported

• Files reviewed: 9/13 changed files
• Comments generated: 2