[pull] main from microsoft:main

.github/CODEOWNERS

@@ -18,3 +18,12 @@ src/vs/workbench/services/extensions/common/extensionPoints.json @TylerLeonhardt
 # Adding entries here lets a new .js/.cjs/.mjs file land in the repo;
 # review is required to make sure TypeScript is not a better choice.
 .eslint-allowed-javascript-files @alexr00 @alexdima @sbatten @TylerLeonhardt
+
+# Agents Window architecture specifications and their routing policy.
+# These files describe stable contracts and should not change for routine fixes.
+/src/vs/sessions/*.md @sandy081
+/src/vs/sessions/contrib/layout/browser/*.md @sandy081
+/src/vs/sessions/contrib/providers/*/*.md @sandy081
+/.github/instructions/sessions.instructions.md @sandy081
+/.github/skills/sessions/SKILL.md @sandy081
+/.github/skills/chat-customizations-editor/SKILL.md @sandy081

.github/skills/chat-customizations-editor/SKILL.md

@@ -11,13 +11,15 @@ Split-view management pane for AI customization items across workspace, user, ex
 
 ## Spec
 
-**`src/vs/sessions/AI_CUSTOMIZATIONS.md`** — always read before making changes, always update after.
+**`src/vs/sessions/AI_CUSTOMIZATIONS.md`** — read for ownership and interface
+contracts. Update it only when those contracts change; behavior and regressions
+belong in focused tests.
 
 ## Key Folders
 
 | Folder | What |
 |--------|------|
-| `src/vs/workbench/contrib/chat/common/` | `ICustomizationHarnessService`, `ISectionOverride`, `IStorageSourceFilter` — shared interfaces and filter helpers |
+| `src/vs/workbench/contrib/chat/common/` | `ICustomizationHarnessService`, `ISectionOverride`, `ICustomizationItemProvider` — shared interfaces |
 | `src/vs/workbench/contrib/chat/browser/aiCustomization/` | Management editor, list widgets (prompts, MCP, plugins), harness service registration |
 | `src/vs/sessions/contrib/chat/browser/` | Sessions-window overrides (harness service, workspace service) |
 | `src/vs/sessions/contrib/sessions/browser/` | Sessions tree view counts and toolbar |
@@ -26,26 +28,25 @@ When changing harness descriptor interfaces or factory functions, verify both co
 
 ## Key Interfaces
 
-- **`IHarnessDescriptor`** — drives all UI behavior declaratively (hidden sections, button overrides, file filters, agent gating). See spec for full field reference.
+- **`IHarnessDescriptor`** — drives harness behavior declaratively (hidden sections, button overrides, item providers, agent gating). See spec for the stable ownership contract.
 - **`ISectionOverride`** — per-section button customization (command invocation, root file creation, type labels, file extensions).
-- **`IStorageSourceFilter`** — controls which storage sources and user roots are visible per harness/type.
-- **`IExternalCustomizationItemProvider`** / **`IExternalCustomizationItem`** — internal interfaces (in `customizationHarnessService.ts`) for extension-contributed providers that supply items directly. These mirror the proposed extension API types.
+- **`ICustomizationItemProvider`** / **`ICustomizationItem`** — internal interfaces (in `customizationHarnessService.ts`) for extension-contributed providers that supply items directly. These mirror the proposed extension API types.
 
 Principle: the UI widgets read everything from the descriptor — no harness-specific conditionals in widget code.
 
 ## Extension API (`chatSessionCustomizationProvider`)
 
-The proposed API in `src/vscode-dts/vscode.proposed.chatSessionCustomizationProvider.d.ts` lets extensions register customization providers. Changes to `IExternalCustomizationItem` or `IExternalCustomizationItemProvider` must be kept in sync across the full chain:
+The proposed API in `src/vscode-dts/vscode.proposed.chatSessionCustomizationProvider.d.ts` lets extensions register customization providers. Changes to `ICustomizationItem` or `ICustomizationItemProvider` must be kept in sync across the full chain:
 
 | Layer | File | Type |
 |-------|------|------|
 | Extension API | `vscode.proposed.chatSessionCustomizationProvider.d.ts` | `ChatSessionCustomizationItem` |
 | IPC DTO | `extHost.protocol.ts` | `IChatSessionCustomizationItemDto` |
 | ExtHost mapping | `extHostChatAgents2.ts` | `$provideChatSessionCustomizations()` |
 | MainThread mapping | `mainThreadChatAgents2.ts` | `provideChatSessionCustomizations` callback |
-| Internal interface | `customizationHarnessService.ts` | `IExternalCustomizationItem` |
+| Internal interface | `customizationHarnessService.ts` | `ICustomizationItem` |
 
-When adding fields to `IExternalCustomizationItem`, update all five layers. The proposed API `.d.ts` is additive-only (new optional fields are backward-compatible and do not require a version bump).
+When adding fields to `ICustomizationItem`, update all five layers. The proposed API `.d.ts` is additive-only (new optional fields are backward-compatible and do not require a version bump).
 
 ## Testing
 

.github/skills/policy-and-managed-settings/github-managed-settings.md

@@ -222,6 +222,32 @@ delivery slot for the managed value.
 | `projectManagedSettings(values, definitions, onWarn?)` | Keeps only declared keys whose runtime value **matches the declared type**. Undeclared keys and type mismatches are **dropped (validated, never coerced)**, with an optional warning. |
 | `pickManagedSettings(nativeMdm, server, file)` | Merges the channels **per key** by precedence (native MDM → server → file): the highest-precedence channel that sets a key wins, lower channels fill in keys the higher ones leave unset, and every contribution is recorded for provenance. **The extension point when adding a new channel** — extend the `ManagedSettingsChannel` union, the `MANAGED_SETTINGS_CHANNELS` order, and this function together. |
 | `managedSettingValue(key)` | Builds the standard pass-through `value` callback `policyData => policyData.managedSettings?.[key]`. Use for the common "lock to the managed value, else fall through" case (see [Declaring a managed setting](#declaring-a-managed-setting-on-a-policy)). |
+| `thirdPartyAgentEnabledValue(policyData)` | Shared `value` callback for the third-party harness policies (see [Governance presence](#governance-presence-disables-the-third-party-harnesses)). |
+
+### Governance presence disables the third-party harnesses
+
+`IPolicyData.managedSettingsActive` is `true` when **any** channel supplies **any** managed
+setting — i.e. the user is governed at all, independent of which keys were set. It is set in
+`AccountPolicyService.getPolicyData` from `pickManagedSettings(...).activeSources`, and unlike
+`IPolicyData.managedSettings` it is **not** projected onto the keys VS Code declares, so it also
+reflects runtime-owned keys VS Code never reads.
+
+The `Claude3PIntegration` and `Codex3PIntegration` policies both use
+`thirdPartyAgentEnabledValue`, which forces its setting to `false` when the account disables
+chat preview features **or** when `managedSettingsActive` is `true`. Rationale: managed settings
+are composed and enforced by the Copilot runtime and never reach the Claude or Codex harnesses,
+so leaving those harnesses available would hand a governed user an ungoverned path around every
+control the enterprise set. This mirrors the runtime-owned `sandbox.enabled` floor retiring the
+local harness (`IAgentHostEnablementService.managedSandboxEnforced`).
+
+Invariants:
+
+- The rule keys off **presence**, not a value, so the policies deliberately declare **no**
+  `managedSettings` keys — they must not be added to the native MDM watcher schema.
+- `AccountPolicyService.resolvePolicyValue` probes for this presence dependence (re-evaluating
+  the callback with `managedSettingsActive: false`) so **Developer: Policy Diagnostics**
+  attributes the value to the governing channel rather than to the account.
+- The `value` callback stays pure and deterministic — attribution evaluates it more than once.
 
 ### Normalization: the structured-key descriptor table
 

.github/skills/sessions/SKILL.md

@@ -72,9 +72,26 @@ that preserve these boundaries:
 - Shared workbench changes represent shared capability, not Sessions-specific
   policy.
 
-Update a specification when its architecture or durable behavior changes. Do not
-add implementation chronology, rejected approaches, or bug narratives to a
-specification.
+### Specification edit gate
+
+Bug fixes do not update specifications when they restore an existing contract.
+Before editing an authoritative specification, identify all three:
+
+1. the existing ownership, interface, lifecycle, state-machine, persistence, or
+   cross-component contract that intentionally changes;
+2. the implementation surfaces affected by that contract change;
+3. why a regression test and a brief code comment cannot fully represent it.
+
+If any answer is missing, leave the specification unchanged. Put concrete
+behavior in a focused test, keep a non-obvious implementation constraint beside
+the owning code, and preserve investigation history in the issue or pull
+request.
+
+Update a specification only when component ownership, an interface or lifecycle
+contract, a state machine, persistence, or a cross-component invariant changes.
+Do not update specifications for styling, copy, action placement, telemetry
+fields, settings defaults, implementation algorithms, or individual bug fixes.
+Those details belong in code and focused tests.
 
 ## 5. Validate proportionally
 

build/azure-pipelines/alpine/product-build-alpine-node-modules.yml

@@ -90,7 +90,6 @@ jobs:
           mkdir -p .build/nodejs-musl
           NODE_VERSION=$(grep '^target=' remote/.npmrc | cut -d '"' -f 2)
           BUILD_ID=$(grep '^ms_build_id=' remote/.npmrc | cut -d '"' -f 2)
-          az extension add --name azure-devops --upgrade --only-show-errors
           az artifacts universal download \
             --organization "https://dev.azure.com/monacotools" \
             --project "Monaco" \

build/azure-pipelines/alpine/product-build-alpine.yml

@@ -106,6 +106,10 @@ jobs:
         condition: and(succeeded(), ne(variables['NPM_REGISTRY'], 'none'))
         displayName: Setup NPM Authentication
 
+      - template: ../common/foundry-local.yml@self
+        parameters:
+          phase: prepare
+
       - task: Docker@1
         inputs:
           azureSubscriptionEndpoint: vscode
@@ -135,7 +139,6 @@ jobs:
           mkdir -p .build/nodejs-musl
           NODE_VERSION=$(grep '^target=' remote/.npmrc | cut -d '"' -f 2)
           BUILD_ID=$(grep '^ms_build_id=' remote/.npmrc | cut -d '"' -f 2)
-          az extension add --name azure-devops --upgrade --only-show-errors
           az artifacts universal download \
             --organization "https://dev.azure.com/monacotools" \
             --project "Monaco" \
@@ -174,6 +177,10 @@ jobs:
         displayName: Install dependencies
         condition: and(succeeded(), ne(variables.NODE_MODULES_RESTORED, 'true'))
 
+      - template: ../common/foundry-local.yml@self
+        parameters:
+          phase: install
+
       - script: node build/azure-pipelines/common/checkNativeOptionalDeps.ts
         displayName: Verify native optional dependency binaries
 

build/azure-pipelines/common/disableFoundryLocalInstall.ts

@@ -3,22 +3,6 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-import * as fs from 'fs';
-import * as path from 'path';
+import { disableFoundryLocalInstall } from './foundryLocalInstall.ts';
 
-const packageJsonPath = path.resolve(import.meta.dirname, '../../..', 'package.json');
-const packageJson = JSON.parse(fs.readFileSync(packageJsonPath, 'utf8')) as {
-	dependencies?: Record<string, string>;
-	allowScripts?: Record<string, boolean>;
-};
-const allowScripts = packageJson.allowScripts;
-const foundryLocalVersion = packageJson.dependencies?.['foundry-local-sdk'];
-const foundryLocalKey = foundryLocalVersion ? `foundry-local-sdk@${foundryLocalVersion}` : undefined;
-
-if (!allowScripts || !foundryLocalKey || allowScripts[foundryLocalKey] !== true) {
-	throw new Error('Expected an approved, pinned foundry-local-sdk install script in package.json');
-}
-
-allowScripts[foundryLocalKey] = false;
-fs.writeFileSync(packageJsonPath, `${JSON.stringify(packageJson, undefined, 2)}\n`);
-console.log(`Disabled ${foundryLocalKey} install script for this CI job`);
+disableFoundryLocalInstall();

build/azure-pipelines/common/foundry-local.yml

@@ -0,0 +1,18 @@
+parameters:
+  - name: phase
+    type: string
+    values:
+      - prepare
+      - install
+
+steps:
+  - ${{ if eq(parameters.phase, 'prepare') }}:
+    - task: NuGetAuthenticate@1
+      displayName: Setup NuGet Authentication
+
+    - script: node build/azure-pipelines/common/disableFoundryLocalInstall.ts
+      displayName: Disable Foundry Local Native Install
+
+  - ${{ if eq(parameters.phase, 'install') }}:
+    - script: node build/azure-pipelines/common/foundryLocalInstall.ts
+      displayName: Install Foundry Local Native Dependencies

build/azure-pipelines/common/foundryLocalInstall.ts

@@ -0,0 +1,121 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { execFileSync } from 'child_process';
+import { createHash } from 'crypto';
+import * as fs from 'fs';
+import * as path from 'path';
+import { fetchCoreLibraries, getStandardArtifacts, type IFoundryDependencyVersions, requiredCoreLibraryNames, supportsCoreLibraryTarget, VSCODE_NUGET_FEED } from '../../dictation-runtime/nuget.ts';
+
+const repositoryRoot = path.resolve(import.meta.dirname, '../../..');
+const packageName = 'foundry-local-sdk';
+const credentialTokenEnvironmentVariable = 'VSS_NUGET_ACCESSTOKEN';
+const expectedInstallerUtilsHash = '0831c932b10389283e805f88a204b0f6a5a8053f2ee520e56a0f0adf1352aa8b';
+
+type RootPackageJson = {
+	dependencies?: Record<string, string>;
+	allowScripts?: Record<string, boolean>;
+};
+
+type FoundryPackageJson = {
+	version?: string;
+	scripts?: Record<string, string>;
+};
+
+function readJson<T>(filePath: string): T {
+	return JSON.parse(fs.readFileSync(filePath, 'utf8')) as T;
+}
+
+function getPinnedPackage(root: string): { packageJsonPath: string; packageJson: RootPackageJson; allowScripts: Record<string, boolean>; allowScriptsKey: string } {
+	const packageJsonPath = path.join(root, 'package.json');
+	const packageJson = readJson<RootPackageJson>(packageJsonPath);
+	const allowScripts = packageJson.allowScripts;
+	const version = packageJson.dependencies?.[packageName];
+	const allowScriptsKey = version ? `${packageName}@${version}` : undefined;
+
+	if (!allowScripts || !version || !allowScriptsKey || allowScripts[allowScriptsKey] !== true) {
+		throw new Error(`Expected an approved, pinned ${packageName} install script in package.json`);
+	}
+
+	return { packageJsonPath, packageJson, allowScripts, allowScriptsKey };
+}
+
+export function disableFoundryLocalInstall(root = repositoryRoot): void {
+	const { packageJsonPath, packageJson, allowScripts, allowScriptsKey } = getPinnedPackage(root);
+	allowScripts[allowScriptsKey] = false;
+	fs.writeFileSync(packageJsonPath, `${JSON.stringify(packageJson, undefined, 2)}\n`);
+	console.log(`Disabled ${allowScriptsKey} install script for this CI job`);
+}
+
+function validateInstallerUtils(installerUtilsPath: string): void {
+	const contents = fs.readFileSync(installerUtilsPath);
+	const actualHash = createHash('sha256').update(contents).digest('hex');
+
+	if (actualHash !== expectedInstallerUtilsHash) {
+		throw new Error(`Unexpected ${packageName} installer utility hash ${actualHash}`);
+	}
+}
+
+function runLifecycleScript(packageRoot: string, relativeScriptPath: string): void {
+	execFileSync(process.execPath, [path.join(packageRoot, relativeScriptPath)], {
+		cwd: packageRoot,
+		stdio: 'inherit'
+	});
+}
+
+export async function installFoundryLocal(root = repositoryRoot): Promise<void> {
+	if (!process.env[credentialTokenEnvironmentVariable]) {
+		throw new Error(`${credentialTokenEnvironmentVariable} was not set by NuGetAuthenticate`);
+	}
+
+	const rootPackageJson = readJson<RootPackageJson>(path.join(root, 'package.json'));
+	const version = rootPackageJson.dependencies?.[packageName];
+	const allowScriptsKey = version ? `${packageName}@${version}` : undefined;
+	if (!version || !allowScriptsKey || rootPackageJson.allowScripts?.[allowScriptsKey] !== false) {
+		throw new Error(`Expected the pinned ${packageName} install script to be disabled before installation`);
+	}
+
+	const packageRoot = path.join(root, 'node_modules', packageName);
+	const packageJson = readJson<FoundryPackageJson>(path.join(packageRoot, 'package.json'));
+	if (packageJson.version !== version) {
+		throw new Error(`Expected ${packageName}@${version}, found ${packageJson.version ?? 'an unknown version'}`);
+	}
+	if (packageJson.scripts?.preinstall !== 'node script/preinstall.cjs' || packageJson.scripts.install !== 'node script/install-standard.cjs') {
+		throw new Error(`Unexpected ${packageName}@${version} lifecycle scripts`);
+	}
+
+	validateInstallerUtils(path.join(packageRoot, 'script', 'install-utils.cjs'));
+	runLifecycleScript(packageRoot, 'script/preinstall.cjs');
+
+	const target = `${process.platform}-${process.arch}`;
+	if (!supportsCoreLibraryTarget(target)) {
+		console.warn(`[foundry-local] Unsupported platform: ${target}. Skipping.`);
+		return;
+	}
+
+	const dependencies = readJson<IFoundryDependencyVersions>(path.join(packageRoot, 'deps_versions.json'));
+	const artifacts = getStandardArtifacts(target, dependencies);
+	const binDir = path.join(packageRoot, 'foundry-local-core', target);
+	await fetchCoreLibraries(target, artifacts, binDir, { feeds: [VSCODE_NUGET_FEED], skipIfPresent: true });
+
+	const missingFiles = requiredCoreLibraryNames(target).filter(file => !fs.existsSync(path.join(binDir, file)));
+	if (missingFiles.length > 0) {
+		throw new Error(`[foundry-local] Missing required native libraries for ${target}: ${missingFiles.join(', ')}`);
+	}
+
+	const coreVersion = dependencies['foundry-local-core'].nuget;
+	const platformPackageJson = {
+		name: `@foundry-local-core/${target}`,
+		version: coreVersion,
+		description: `Native binaries for Foundry Local SDK (${target})`,
+		private: true,
+	};
+	fs.writeFileSync(path.join(binDir, 'package.json'), JSON.stringify(platformPackageJson, undefined, 2));
+	console.log('[foundry-local] Installation complete.');
+}
+
+if (import.meta.filename === process.argv[1]) {
+	await installFoundryLocal();
+}

build/azure-pipelines/common/sanity-tests.yml

@@ -102,6 +102,9 @@ jobs:
           displayName: Create Crash Dumps Directory
 
       - ${{ if and(eq(parameters.os, 'windows'), eq(parameters.arch, 'arm64')) }}:
+        - task: NuGetAuthenticate@1
+          displayName: Setup NuGet Authentication
+
         - script: |
             @echo off
             setlocal enabledelayedexpansion
@@ -117,7 +120,7 @@ jobs:
               if exist "!SDK_ROOT!" rmdir /s /q "!SDK_ROOT!"
 
               set "SDK_PACKAGE=$(Agent.TempDirectory)\windows-sdk-build-tools.nupkg"
-              curl.exe -fsSL --retry 5 --retry-delay 2 --retry-all-errors "https://api.nuget.org/v3-flatcontainer/microsoft.windows.sdk.buildtools/!PACKAGE_VERSION!/microsoft.windows.sdk.buildtools.!PACKAGE_VERSION!.nupkg" -o "!SDK_PACKAGE!"
+              curl.exe -fsSL --retry 5 --retry-delay 2 --retry-all-errors -u "vscode:%VSS_NUGET_ACCESSTOKEN%" "https://pkgs.dev.azure.com/monacotools/Monaco/_packaging/vscode/nuget/v3/flat2/microsoft.windows.sdk.buildtools/!PACKAGE_VERSION!/microsoft.windows.sdk.buildtools.!PACKAGE_VERSION!.nupkg" -o "!SDK_PACKAGE!"
 
               set "ACTUAL_HASH="
               for /f "skip=1" %%A in ('certutil -hashfile "!SDK_PACKAGE!" SHA256') do if not defined ACTUAL_HASH set "ACTUAL_HASH=%%A"