Generalize model picker to be used with Claude

[TylerLeonhardt]

So that it has a model picker on the welcome chat.

Co-authored-by: Copilot copilot@github.com

[github-actions]

Screenshot Changes

Base: d0b379e4 Current: 2bf8dacb

Changed (2)

chat/aiCustomizations/aiCustomizationManagementEditor/McpBrowseMode/Light

Before	After

editor/inlineCompletions/other/JumpToHint/Dark

Before	After

[Copilot]

Pull request overview

This PR generalizes the Copilot Chat Sessions “Model” picker so it can be shown for Claude Code sessions as well, while persisting the selected model per session type.

Changes:

• Introduces SessionModelPicker and modelPickerStorageKey() to unify model selection, storage, and provider syncing per sessionType.
• Expands the New Session config “Model” menu contribution to also apply to Claude Code sessions.
• Adds a new browser test suite covering storage key scoping, model filtering, and picker initialization behavior.

Show a summary per file

File	Description
src/vs/sessions/contrib/copilotChatSessions/browser/copilotChatSessionsActions.ts	Replaces inline picker wiring with a reusable SessionModelPicker, adds per-session-type storage keys, and enables picker for Claude sessions.
src/vs/sessions/contrib/copilotChatSessions/test/browser/modelPickerDelegate.test.ts	Adds tests for model filtering and per-session-type persistence/initialization.
src/vs/sessions/contrib/copilotChatSessions/COPILOT_CHAT_SESSIONS_PROVIDER.md	Updates docs to reflect the unified model picker for CLI + Claude.

Copilot's findings

Comments suppressed due to low confidence (2)

src/vs/sessions/contrib/copilotChatSessions/test/browser/modelPickerDelegate.test.ts:106

• These fixtures use session type strings like 'copilot-cli'/'copilot-cloud'. The production session type IDs are defined as constants (e.g. COPILOT_CLI_SESSION_TYPE = copilotcli, COPILOT_CLOUD_SESSION_TYPE = copilot-cloud-agent). Please switch the test data to use those constants so the model filtering behavior matches real sessions.

	test('filters models by session type', () => {
		const models = [
			makeModel('cli-model', 'copilot-cli'),
			makeModel('cloud-model', 'copilot-cloud'),
			makeModel('claude-model', 'claude-code'),
		];

src/vs/sessions/contrib/copilotChatSessions/test/browser/modelPickerDelegate.test.ts:176

• This test switches to sessionType: 'copilot-cli', but the actual CLI session type ID is COPILOT_CLI_SESSION_TYPE (copilotcli). Using the wrong ID here makes the asserted storage key (sessions.modelPicker.copilot-cli...) diverge from what SessionModelPicker will produce in production. Prefer importing the session type constants and asserting against modelPickerStorageKey(COPILOT_CLI_SESSION_TYPE) / modelPickerStorageKey(CLAUDE_CODE_SESSION_TYPE) instead of hard-coded strings.

		const { instantiationService, storage, activeSession } = stubServices(disposables, {
			models: allModels,
			activeSession: { providerId: 'default-copilot', sessionId: 's1', sessionType: 'copilot-cli' },
		});

• Files reviewed: 3/3 changed files
• Comments generated: 2