Summary

Adds a desktop Agents-window Remotes page to Customizations so users can manage which known remote locations appear in the New Session picker without going through separate connection pickers.

• Adds entry points in both the Customizations dialog and the sidebar below the Sessions list, with a shared live badge counting enabled remotes.
• Reuses the Plugins tree/group-header/switch controls and standard page insets. Groups are WSL (Windows only), SSH, Tunnels, and Dev Containers.
• Combines SSH configuration, installed WSL distributions, account tunnels, local Docker Dev Containers, and already registered locations. Refresh failures are shown as warning icons on the affected group, with simple tooltips and diagnostic details in the Window log.
• Uses existing registration/removal mechanisms and leaves the location-picker implementation unchanged. Adds registration-only APIs for WSL and Dev Container workspaces, and ensures offline SSH/WSL registrations publish their providers.
• Includes keyboard navigation, accessibility help and an accessible view, discovery cancellation, focused regression tests, and themed fixtures.

No linked issue; this draft is a prototype requested directly during development.

Behavior and limitations

• Switching on registers the location without explicitly connecting. Existing automatic-connection settings still apply.
• Switching off may disconnect/remove the provider. Dev Container removal here forgets the location; it does not delete the container.
• Local Dev Container discovery uses desktop IPC, not a new Agent Host Protocol requirement. Containers without a local source folder are shown with disabled switches.
• Badge counts come from registered enabled locations, independently of search filtering or connection status; zero-count badges are hidden.
• Live WSL and authenticated tunnel flows have not been exercised. Docker enumeration and registration are covered by tests, but live Docker discovery was unavailable in the isolated UI profile.

How to test

1. In a desktop Agents window with chat.remoteAgentHostsEnabled enabled, select Remotes below the Sessions list.
2. Confirm the dialog opens the Remotes tree, with WSL omitted on macOS/Linux, and that the page aligns with Plugins.
3. Toggle a known remote. Confirm both navigation badges update together and the remote is added/removed in the New Session location picker. Set chat.remoteAgentHostsAutoConnect to false to test offline registration.
4. Search, collapse/expand groups, and use Tab/Space on the switches. Check that search does not change the enabled-count badges.
5. Reopen/reload and verify the registered locations and badges persist. Simulate a discovery failure and inspect the affected group's warning tooltip; retry with Refresh.
6. Use accessibility help and the accessible view while focused on Remotes.

Validation

Rebased without conflicts onto origin/main at f82f4adff5e; git range-diff confirmed the feature commit was unchanged by the rebase.

• npm run compile-client -- passed, including client type checking. The first attempt detected the upstream SDK version mismatch; npm run install-fast restored the declared dependencies, and the subsequent compile passed.
• git diff --name-only --diff-filter=ACM -z origin/main...HEAD -- '*.ts' | xargs -0 npm run eslint -- -- passed, 32 changed TypeScript files.
• npm run valid-layers-check -- passed.
• npm run stylelint -- src/vs/sessions/contrib/providers/remoteAgentHost/browser/media/remotesWidget.css src/vs/workbench/contrib/chat/browser/aiCustomization/media/aiCustomizationManagement.css -- passed, with 96 pre-existing design-token suggestions in the shared stylesheet.
• git diff --check -- passed. Commit hygiene hooks also passed.
• Focused regression selection below -- 232 passed after rebase.

./scripts/test.sh \
  --run src/vs/platform/agentHost/test/common/devContainerAgentHostIpc.test.ts \
  --run src/vs/platform/agentHost/test/electron-browser/wslRemoteAgentHostService.test.ts \
  --run src/vs/platform/agentHost/test/node/devContainerAgentHostService.test.ts \
  --run src/vs/sessions/contrib/providers/remoteAgentHost/test/browser/devContainerAgentHostService.test.ts \
  --run src/vs/sessions/contrib/providers/remoteAgentHost/test/browser/entryDrivenProviderContribution.test.ts \
  --run src/vs/sessions/contrib/providers/remoteAgentHost/test/browser/sshAgentHost.contribution.test.ts \
  --run src/vs/sessions/contrib/providers/remoteAgentHost/test/browser/wslAgentHost.contribution.test.ts \
  --run src/vs/sessions/contrib/providers/remoteAgentHost/test/browser/remotesModel.test.ts \
  --run src/vs/sessions/contrib/providers/remoteAgentHost/test/browser/remotesWidget.test.ts \
  --run src/vs/sessions/contrib/sessions/test/browser/customizationsToolbar.test.ts \
  --run src/vs/workbench/contrib/chat/test/browser/aiCustomization/aiCustomizationManagementEditor.test.ts \
  --reporter dot

Before rebase, live macOS Dev 1.144.0 scenarios passed for sidebar/dialog entry points, Plugins inset parity, warning tooltips, keyboard navigation, accessibility help/focus restoration, actual picker addition/removal, and synchronized badges across filtering and reload. Dark/light, narrow, empty, and Windows-grouping fixtures were inspected. These UI scenarios were not rerun after rebase. Full smoke/integration suites and Windows/Linux live validation were not run.