Document GitHub issue and pull request context workflows

[ntrogh]

Product change

• Sources: Chat: Render pasted GitHub issue links vscode#334068 and sessions: Consolidate GitHub and remote workspace options vscode#334084
• Merged: 2026-09-02T19:43:13Z to 2026-09-03T02:24:56Z

GitHub issues and pull requests are now attached from Add Context through separate Issue... and Pull Request... actions, with a repository picker when multiple repositories are available. Pasting a canonical GitHub issue or pull request URL creates a compact inline reference while preserving the complete URL in the prompt. In the Agents composer, pasted links are not automatically attached as context. The paste behavior is controlled by chat.pasteGitHubLinksAsReferences, which defaults to true.

Why the docs need an update

The Chat and Agents guidance still describes the previous combined Issue/PR control and does not explain the pasted-reference behavior, the distinction between a reference and attached context, or the new setting.

Suggested documentation

• docs/chat/copilot-chat-context.md: Replace the combined Issue/PR instructions with the separate Add Context actions and describe repository selection.
• docs/agents/run/agents-window.md: Explain how pasted GitHub links appear in the Agents composer and that they are not automatically attached as context.
• docs/agents/reference/ai-settings.md: Add chat.pasteGitHubLinksAsReferences and its default.

Details to verify

• Setting: chat.pasteGitHubLinksAsReferences.
• Default: true.
• The original URL, including fragments, remains in the agent-facing prompt text.
• The Issue and Pull Request attachment changes in PR 334084 are not controlled by the consolidated remote workspaces experiment.

Acceptance criteria

• Chat and Agents instructions match the current GitHub issue and pull request context UI.
• The difference between pasted references and attached context is clear.
• The setting identifier and default are accurate.