Sessions: customization improvements (#298122)

* Refactor: unified IStorageSourceFilter replaces per-field filtering APIs

Replace visibleStorageSources, getVisibleStorageSources(type), and
excludedUserFileRoots with a single getStorageSourceFilter(type)
returning IStorageSourceFilter with sources and includedUserFileRoots.

- New IStorageSourceFilter interface with allowlist-based user root filtering
- Shared applyStorageSourceFilter helper for list widget and counts
- Sessions: hooks=workspace-only, prompts=all roots, others=CLI roots
- AgenticPromptsService.getSourceFolders override for creation targeting
- Remove chat.customizationsMenu.userStoragePath setting
- Simplify resolveUserTargetDirectory to pure getSourceFolders delegate
- Update all consumer call sites and tests

* Fix sidebar/editor count mismatch and rename preferManualCreation

Count functions now use the same data sources as loadItems():
- Agents: getCustomAgents() instead of listPromptFilesForStorage
- Skills: findAgentSkills()
- Prompts: getPromptSlashCommands() filtering out skills
- Instructions: listPromptFiles() + listAgentInstructions()
- Hooks: listPromptFiles()

Rename preferManualCreation to isSessionsWindow for clarity.
Add 50 tests for applyStorageSourceFilter and customizationCounts.

* Add Developer: Customizations Debug command and fix hooks.json

- Debug command opens untitled editor with full pipeline diagnostics
- Rename 'Open Chat Customizations (Preview)' to 'Open Customizations (Preview)'
- Fix hooks.json: add version field, use bash instead of command
- Derive hook events from COPILOT_CLI_HOOK_TYPE_MAP schema automatically

* Update AI_CUSTOMIZATIONS.md spec

- Document IStorageSourceFilter, AgenticPromptsService, count consistency
- Add debug panel section and updated file structure
- Reflect isSessionsWindow rename

* Remove verbose debug logs from list widget

The Developer: Customizations Debug command provides better diagnostics.
Remove noisy info-level logs that dump every item URI on every load.

* Code review fixes: cache copilotRoot, remove dead getter, fix JSDoc

* Add AI customizations manual test plan with 5 scenarios

Author: joshspicer

src/vs/sessions/AI_CUSTOMIZATIONS.md

@@ -15,6 +15,7 @@ src/vs/workbench/contrib/chat/browser/aiCustomization/
 ├── aiCustomizationManagementEditor.ts          # SplitView list/editor
 ├── aiCustomizationManagementEditorInput.ts     # Singleton input
 ├── aiCustomizationListWidget.ts                # Search + grouped list
+├── aiCustomizationDebugPanel.ts                # Debug diagnostics panel
 ├── aiCustomizationWorkspaceService.ts          # Core VS Code workspace service impl
 ├── customizationCreatorService.ts              # AI-guided creation flow
 ├── mcpListWidget.ts                            # MCP servers section
@@ -23,7 +24,7 @@ src/vs/workbench/contrib/chat/browser/aiCustomization/
     └── aiCustomizationManagement.css
 
 src/vs/workbench/contrib/chat/common/
-└── aiCustomizationWorkspaceService.ts          # IAICustomizationWorkspaceService interface
+└── aiCustomizationWorkspaceService.ts          # IAICustomizationWorkspaceService + IStorageSourceFilter
 ```
 
 The tree view and overview live in `vs/sessions` (sessions window only):
@@ -42,23 +43,77 @@ Sessions-specific overrides:
 
 ```
 src/vs/sessions/contrib/chat/browser/
-└── aiCustomizationWorkspaceService.ts          # Sessions workspace service override
+├── aiCustomizationWorkspaceService.ts          # Sessions workspace service override
+└── promptsService.ts                           # AgenticPromptsService (CLI user roots)
 src/vs/sessions/contrib/sessions/browser/
-├── customizationCounts.ts                      # Source count utilities
+├── customizationCounts.ts                      # Source count utilities (type-aware)
 └── customizationsToolbar.contribution.ts       # Sidebar customization links
 ```
 
 ### IAICustomizationWorkspaceService
 
 The `IAICustomizationWorkspaceService` interface controls per-window behavior:
 
-| Property | Core VS Code | Sessions Window |
+| Property / Method | Core VS Code | Sessions Window |
 |----------|-------------|----------|
-| `managementSections` | All sections except Models | Same |
-| `visibleStorageSources` | workspace, user, extension, plugin | workspace, user only |
-| `preferManualCreation` | `false` (AI generation primary) | `true` (file creation primary) |
+| `managementSections` | All sections except Models | Same minus MCP |
+| `getStorageSourceFilter(type)` | All sources, no user root filter | Per-type (see below) |
+| `isSessionsWindow` | `false` | `true` |
 | `activeProjectRoot` | First workspace folder | Active session worktree |
 
+### IStorageSourceFilter
+
+A unified per-type filter controlling which storage sources and user file roots are visible.
+Replaces the old `visibleStorageSources`, `getVisibleStorageSources(type)`, and `excludedUserFileRoots`.
+
+```typescript
+interface IStorageSourceFilter {
+  sources: readonly PromptsStorage[];         // Which storage groups to display
+  includedUserFileRoots?: readonly URI[];     // Allowlist for user roots (undefined = all)
+}
+```
+
+The shared `applyStorageSourceFilter()` helper applies this filter to any `{uri, storage}` array.
+
+**Sessions filter behavior by type:**
+
+| Type | sources | includedUserFileRoots |
+|------|---------|----------------------|
+| Hooks | `[local]` | N/A |
+| Prompts | `[local, user]` | `undefined` (all roots) |
+| Agents, Skills, Instructions | `[local, user]` | `[~/.copilot, ~/.claude, ~/.agents]` |
+
+**Core VS Code:** All types use `[local, user, extension, plugin]` with no user root filter.
+
+### AgenticPromptsService (Sessions)
+
+Sessions overrides `PromptsService` via `AgenticPromptsService` (in `promptsService.ts`):
+
+- **Discovery**: `AgenticPromptFilesLocator` scopes workspace folders to the active session's worktree
+- **Creation targets**: `getSourceFolders()` override replaces VS Code profile user roots with `~/.copilot/{subfolder}` for CLI compatibility
+- **Hook folders**: Falls back to `.github/hooks` in the active worktree
+
+### Count Consistency
+
+`customizationCounts.ts` uses the **same data sources** as the list widget's `loadItems()`:
+
+| Type | Data Source | Notes |
+|------|-------------|-------|
+| Agents | `getCustomAgents()` | Parsed agents, not raw files |
+| Skills | `findAgentSkills()` | Parsed skills with frontmatter |
+| Prompts | `getPromptSlashCommands()` | Filters out skill-type commands |
+| Instructions | `listPromptFiles()` + `listAgentInstructions()` | Includes AGENTS.md, CLAUDE.md etc. |
+| Hooks | `listPromptFiles()` | Raw hook files |
+
+### Debug Panel
+
+Toggle via Command Palette: "Toggle Customizations Debug Panel". Shows a 4-stage pipeline view:
+
+1. **Raw PromptsService data** — per-storage file lists + type-specific extras
+2. **After applyStorageSourceFilter** — what was removed and why
+3. **Widget state** — allItems vs displayEntries with group counts
+4. **Source/resolved folders** — creation targets and discovery order
+
 ## Key Services
 
 - **Prompt discovery**: `IPromptsService` — parsing, lifecycle, storage enumeration

src/vs/sessions/contrib/chat/browser/aiCustomizationWorkspaceService.ts

@@ -4,14 +4,15 @@
  *--------------------------------------------------------------------------------------------*/
 
 import { derived, IObservable } from '../../../../base/common/observable.js';
+import { joinPath } from '../../../../base/common/resources.js';
 import { URI } from '../../../../base/common/uri.js';
-import { IAICustomizationWorkspaceService, AICustomizationManagementSection } from '../../../../workbench/contrib/chat/common/aiCustomizationWorkspaceService.js';
+import { IAICustomizationWorkspaceService, AICustomizationManagementSection, IStorageSourceFilter } from '../../../../workbench/contrib/chat/common/aiCustomizationWorkspaceService.js';
 import { PromptsStorage } from '../../../../workbench/contrib/chat/common/promptSyntax/service/promptsService.js';
 import { ISessionsManagementService } from '../../sessions/browser/sessionsManagementService.js';
 import { IInstantiationService } from '../../../../platform/instantiation/common/instantiation.js';
-import { IUserDataProfilesService } from '../../../../platform/userDataProfile/common/userDataProfile.js';
 import { CustomizationCreatorService } from '../../../../workbench/contrib/chat/browser/aiCustomization/customizationCreatorService.js';
 import { PromptsType } from '../../../../workbench/contrib/chat/common/promptSyntax/promptTypes.js';
+import { IPathService } from '../../../../workbench/services/path/common/pathService.js';
 
 /**
  * Agent Sessions override of IAICustomizationWorkspaceService.
@@ -23,14 +24,32 @@ export class SessionsAICustomizationWorkspaceService implements IAICustomization
 
 	readonly activeProjectRoot: IObservable<URI | undefined>;
 
-	readonly excludedUserFileRoots: readonly URI[];
+	/**
+	 * CLI-accessible user directories for customization file filtering and creation.
+	 */
+	private readonly _cliUserRoots: readonly URI[];
+
+	/**
+	 * Pre-built filter for types that should only show CLI-accessible user roots.
+	 */
+	private readonly _cliUserFilter: IStorageSourceFilter;
 
 	constructor(
 		@ISessionsManagementService private readonly sessionsService: ISessionsManagementService,
 		@IInstantiationService private readonly instantiationService: IInstantiationService,
-		@IUserDataProfilesService userDataProfilesService: IUserDataProfilesService,
+		@IPathService pathService: IPathService,
 	) {
-		this.excludedUserFileRoots = [userDataProfilesService.defaultProfile.promptsHome];
+		const userHome = pathService.userHome({ preferLocal: true });
+		this._cliUserRoots = [
+			joinPath(userHome, '.copilot'),
+			joinPath(userHome, '.claude'),
+			joinPath(userHome, '.agents'),
+		];
+		this._cliUserFilter = {
+			sources: [PromptsStorage.local, PromptsStorage.user],
+			includedUserFileRoots: this._cliUserRoots,
+		};
+
 		this.activeProjectRoot = derived(reader => {
 			const session = this.sessionsService.activeSession.read(reader);
 			return session?.worktree ?? session?.repository;
@@ -52,19 +71,30 @@ export class SessionsAICustomizationWorkspaceService implements IAICustomization
 		// AICustomizationManagementSection.McpServers,
 	];
 
-	readonly visibleStorageSources: readonly PromptsStorage[] = [
-		PromptsStorage.local,
-		PromptsStorage.user,
-	];
+	private static readonly _hooksFilter: IStorageSourceFilter = {
+		sources: [PromptsStorage.local],
+	};
 
-	getVisibleStorageSources(type: PromptsType): readonly PromptsStorage[] {
+	private static readonly _allUserRootsFilter: IStorageSourceFilter = {
+		sources: [PromptsStorage.local, PromptsStorage.user],
+	};
+
+	getStorageSourceFilter(type: PromptsType): IStorageSourceFilter {
 		if (type === PromptsType.hook) {
-			return [PromptsStorage.local];
+			return SessionsAICustomizationWorkspaceService._hooksFilter;
+		}
+		if (type === PromptsType.prompt) {
+			// Prompts are shown from all user roots (including VS Code profile)
+			return SessionsAICustomizationWorkspaceService._allUserRootsFilter;
 		}
-		return this.visibleStorageSources;
+		// Other types only show user files from CLI-accessible roots (~/.copilot, ~/.claude, ~/.agents)
+		return this._cliUserFilter;
 	}
 
-	readonly preferManualCreation = true;
+	/**
+	 * Returns the CLI-accessible user directories (~/.copilot, ~/.claude, ~/.agents).
+	 */
+	readonly isSessionsWindow = true;
 
 	async commitFiles(projectRoot: URI, fileUris: URI[]): Promise<void> {
 		const session = this.sessionsService.getActiveSession();

src/vs/sessions/contrib/chat/browser/promptsService.ts

@@ -13,16 +13,47 @@ import { IFileService } from '../../../../platform/files/common/files.js';
 import { ILogService } from '../../../../platform/log/common/log.js';
 import { IWorkspaceContextService, IWorkspaceFolder } from '../../../../platform/workspace/common/workspace.js';
 import { HOOKS_SOURCE_FOLDER } from '../../../../workbench/contrib/chat/common/promptSyntax/config/promptFileLocations.js';
+import { PromptsType } from '../../../../workbench/contrib/chat/common/promptSyntax/promptTypes.js';
+import { IPromptPath, PromptsStorage } from '../../../../workbench/contrib/chat/common/promptSyntax/service/promptsService.js';
 import { IWorkbenchEnvironmentService } from '../../../../workbench/services/environment/common/environmentService.js';
 import { IPathService } from '../../../../workbench/services/path/common/pathService.js';
 import { ISearchService } from '../../../../workbench/services/search/common/search.js';
 import { IUserDataProfileService } from '../../../../workbench/services/userDataProfile/common/userDataProfile.js';
 import { ISessionsManagementService } from '../../sessions/browser/sessionsManagementService.js';
 
 export class AgenticPromptsService extends PromptsService {
+	private _copilotRoot: URI | undefined;
+
 	protected override createPromptFilesLocator(): PromptFilesLocator {
 		return this.instantiationService.createInstance(AgenticPromptFilesLocator);
 	}
+
+	private getCopilotRoot(): URI {
+		if (!this._copilotRoot) {
+			const pathService = this.instantiationService.invokeFunction(accessor => accessor.get(IPathService));
+			this._copilotRoot = joinPath(pathService.userHome({ preferLocal: true }), '.copilot');
+		}
+		return this._copilotRoot;
+	}
+
+	/**
+	 * Override to use ~/.copilot as the user-level source folder for creation,
+	 * instead of the VS Code profile's promptsHome.
+	 */
+	public override async getSourceFolders(type: PromptsType): Promise<readonly IPromptPath[]> {
+		const folders = await super.getSourceFolders(type);
+		const copilotRoot = this.getCopilotRoot();
+		// Replace any user-storage folders with the CLI-accessible ~/.copilot root
+		return folders.map(folder => {
+			if (folder.storage === PromptsStorage.user) {
+				const subfolder = getCliUserSubfolder(type);
+				return subfolder
+					? { ...folder, uri: joinPath(copilotRoot, subfolder) }
+					: folder;
+			}
+			return folder;
+		});
+	}
 }
 
 class AgenticPromptFilesLocator extends PromptFilesLocator {
@@ -91,3 +122,17 @@ class AgenticPromptFilesLocator extends PromptFilesLocator {
 	}
 }
 
+/**
+ * Returns the subfolder name under ~/.copilot/ for a given customization type.
+ * Used to determine the CLI-accessible user creation target.
+ */
+function getCliUserSubfolder(type: PromptsType): string | undefined {
+	switch (type) {
+		case PromptsType.instructions: return 'instructions';
+		case PromptsType.skill: return 'skills';
+		case PromptsType.agent: return 'agents';
+		case PromptsType.prompt: return 'prompts';
+		default: return undefined;
+	}
+}
+

src/vs/sessions/contrib/configuration/browser/configuration.contribution.ts

@@ -30,8 +30,6 @@ Registry.as<IConfigurationRegistry>(Extensions.Configuration).registerDefaultCon
 		'github.copilot.chat.languageContext.typescript.enabled': true,
 		'github.copilot.chat.cli.mcp.enabled': true,
 
-		'chat.customizationsMenu.userStoragePath': '~/.copilot',
-
 		'inlineChat.affordance': 'editor',
 		'inlineChat.renderMode': 'hover',