add pluginUri and extensionId to ICustomizationItem: fix slash command qualification

[aeschli]

No description provided.

[github-actions]

Base: 34402873 Current: 26c7435c

No screenshot changes.

[Copilot]

Pull request overview

Adds richer provenance metadata (extensionId, pluginUri, and resource source) to chat customization items/resources so the workbench and extension host can correctly attribute items (and qualify plugin-backed slash commands) across providers, UI, and RPC boundaries.

Changes:

• Extend proposed API types to surface customization/resource provenance (source, extensionId, pluginUri).
• Thread new fields through workbench ↔ ext host protocol DTOs and conversion code.
• Adjust AI Customization UI normalization/debug output and qualify plugin slash command names.

Show a summary per file

File	Description
src/vscode-dts/vscode.proposed.chatSessionCustomizationProvider.d.ts	Extends customization item proposal with extensionId/pluginUri provenance.
src/vscode-dts/vscode.proposed.chatPromptFiles.d.ts	Adds provenance (source, extensionId, pluginUri) to ChatHook.
src/vs/workbench/contrib/chat/common/customizationHarnessService.ts	Uses plugin URI to canonicalize plugin slash command names; updates harness item shape.
src/vs/workbench/contrib/chat/browser/aiCustomization/aiCustomizationListWidget.ts	Shows extension provenance in item tooltip (now based on extensionId).
src/vs/workbench/contrib/chat/browser/aiCustomization/aiCustomizationItemSource.ts	Normalizes items using extensionId/pluginUri instead of extensionLabel; adjusts storage inference.
src/vs/workbench/contrib/chat/browser/aiCustomization/aiCustomizationDebugPanel.ts	Displays extensionId/pluginUri in debug output.
src/vs/workbench/contrib/chat/browser/agentSessions/agentHost/agentHostLocalCustomizations.ts	Propagates plugin/extension provenance into locally enumerated harness items; improves skill naming fallback.
src/vs/workbench/api/common/extHostChatAgents2.ts	Includes provenance when mapping customization items and hooks into extension API objects/DTOs.
src/vs/workbench/api/common/extHost.protocol.ts	Extends protocol DTOs to carry source, extensionId, and pluginUri.
src/vs/workbench/api/browser/mainThreadChatAgents2.ts	Populates provenance fields when sending hooks/items across the boundary.
extensions/copilot/src/extension/chatSessions/vscode-node/claudeCustomizationProvider.ts	Populates new provenance fields on Claude customization items.
extensions/copilot/src/extension/chatSessions/copilotcli/vscode-node/copilotCLICustomizationProvider.ts	Populates new provenance fields on Copilot CLI customization items.

Copilot's findings

Comments suppressed due to low confidence (2)

src/vs/workbench/contrib/chat/common/customizationHarnessService.ts:171

• extensionLabel was removed from ICustomizationItem, but there is at least one remaining producer that still sets it (src/vs/workbench/contrib/chat/browser/aiCustomization/promptsServiceCustomizationItemProvider.ts, applyBuiltinGroupKeys). That will now fail type-checking; update remaining producers/consumers to use the new extensionId field (or remove the property assignment) so the code compiles.

	/** Storage origin (local, user, extension, plugin). Set by providers that know the source. */
	readonly storage?: PromptsStorage;
	/** The extension identifier that contributed this customization, if any. */
	readonly extensionId: string | undefined;
	/** The URI of the plugin that contributed this customization, if any. */
	readonly pluginUri: URI | undefined;

src/vs/workbench/contrib/chat/browser/aiCustomization/aiCustomizationItemSource.ts:274

• inferStorageAndGroup no longer has a fallback for non-file URIs. Items with a custom scheme and no extensionId/pluginUri will now be inferred as PromptsStorage.user, which breaks existing providers that rely on "non-file scheme => Built-in" (e.g. the Claude provider uses claude-session: URIs for SDK agents). Consider restoring the old non-file fallback (treat as extension/built-in), or require providers to always set extensionId/groupKey for non-file items and update the affected providers accordingly.

	private inferStorageAndGroup(item: ICustomizationItem): { storage: PromptsStorage; groupKey?: string; isBuiltin?: boolean; extensionId?: string; pluginUri?: URI } {
		const groupKey = item.groupKey;
		const isBuiltin = groupKey === BUILTIN_STORAGE;

		if (item.extensionId) {
			const extensionIdentifier = new ExtensionIdentifier(item.extensionId);
			if (isChatExtensionItem(extensionIdentifier, this.productService)) {
				return { storage: PromptsStorage.extension, groupKey: BUILTIN_STORAGE, isBuiltin: true, extensionId: item.extensionId };
			}
			return { storage: PromptsStorage.extension, extensionId: item.extensionId, groupKey, isBuiltin };
		}
		if (item.pluginUri) {
			return { storage: PromptsStorage.plugin, pluginUri: item.pluginUri, groupKey, isBuiltin };
		}

		const uri = item.uri;

		const activeProjectRoot = this.workspaceService.getActiveProjectRoot();
		if (activeProjectRoot && isEqualOrParent(uri, activeProjectRoot)) {
			return { storage: PromptsStorage.local, groupKey, isBuiltin };
		}

		for (const folder of this.workspaceContextService.getWorkspace().folders) {
			if (isEqualOrParent(uri, folder.uri)) {
				return { storage: PromptsStorage.local, groupKey, isBuiltin };
			}
		}

		for (const plugin of this.agentPluginService.plugins.get()) {
			if (isEqualOrParent(uri, plugin.uri)) {
				return { storage: PromptsStorage.plugin, pluginUri: plugin.uri, groupKey, isBuiltin };
			}
		}

		const extensionId = extractExtensionIdFromPath(uri.path);
		if (extensionId) {
			const extensionIdentifier = new ExtensionIdentifier(extensionId);
			if (isChatExtensionItem(extensionIdentifier, this.productService)) {
				return { storage: PromptsStorage.extension, groupKey: BUILTIN_STORAGE, isBuiltin: true, extensionId };
			}
			return { storage: PromptsStorage.extension, extensionId, groupKey, isBuiltin };
		}
		return { storage: PromptsStorage.user };

• Files reviewed: 10/12 changed files
• Comments generated: 3