# Workspace Switcher

## Objective

Move between organizations without mixing their data.

A switcher for users who belong to several workspaces, with clean state isolation on every switch.

## Before You Begin

This feature is being added to an application that already exists and already
works. Do not scaffold a new project, and do not assume a blank slate.

Inspect the codebase first and establish:

- The existing application structure and where code of this kind already lives.
- The framework and version in use.
- The existing design system — colours, spacing, typography, and component conventions.
- Existing UI components you can reuse instead of writing new ones.
- The existing database structure, if this feature needs to persist anything.
- The existing authentication and authorization system, if this feature is user-scoped.
- Dependencies already installed, so you don't add a library that duplicates one.
- The existing test setup and conventions.

Only start writing code once you understand the above. If the application
already implements part of this feature, extend it rather than replacing it.

## Implementation Instructions

1. Show the current workspace at all times, prominently enough that nobody edits the wrong account's data by accident.
2. Resolve the active workspace on the server from the session or the URL. Never trust a client-held value to scope a query.
3. On switch, clear every piece of cached state tied to the previous workspace: query caches, filters, drafts, selections, realtime subscriptions.
4. Map the current route into the new workspace where an equivalent exists, and fall back to that workspace's home when it does not.
5. Do NOT switch by reassigning a variable and re-rendering. Anything that survives the switch is a data leak waiting to be reported.

## UI and UX Requirements

Match the application's existing design system exactly. Reuse its components,
spacing, and typography. This feature should look like it was always there.

## Responsive Requirements

Works on mobile, tablet, and desktop. Touch targets are large enough to hit on a
phone, and nothing overflows horizontally at 320px.

## Accessibility Requirements

- Fully keyboard navigable.
- Correct semantic elements and ARIA roles.
- Visible focus states.
- Meets WCAG AA contrast.
- Dynamic changes are announced to screen readers.
- Respects prefers-reduced-motion.

## Edge Cases

- A user removed from a workspace mid-session must be moved out of it immediately, not at their next page load.
- Suspended, pending-invitation, and past-due workspaces need their own states, not a generic error.
- A stored last-used workspace the user no longer belongs to must fail closed to a valid one.
- Realtime subscriptions and analytics contexts must be torn down and rebuilt, or events cross workspace boundaries.
- Open tabs on the old workspace must not silently start writing to the new one. Scope by tab or reload them.
- Unsaved drafts should be preserved against the workspace they belong to, not carried across or silently discarded.
- A user in a single workspace should not see a switcher at all.

## Testing

Exercise the feature end to end in the running application. Cover every edge case
above, then run the existing test suite and confirm nothing regressed.

## Acceptance Criteria

- [ ] The active workspace is visible on every screen.
- [ ] Workspace scope is resolved server-side on every request.
- [ ] Switching clears caches, filters, drafts, selections, and subscriptions from the previous workspace.
- [ ] The equivalent route is preserved where it exists, with a safe fallback where it does not.
- [ ] Removed, suspended, and pending memberships each have distinct handling.
- [ ] No API response, analytics event, or realtime message crosses workspace boundaries.
- [ ] The feature matches the existing design system.
- [ ] No existing functionality is broken.

## Adaptation Rules

- Match the existing design system. Do not introduce a new colour palette,
  spacing scale, or component library.
- Reuse existing components and utilities wherever they fit.
- Follow the naming, file layout, and code style already present.
- Do not upgrade, replace, or remove existing dependencies to make this
  feature fit. Adapt the feature to the app, not the app to the feature.
- Do not break existing functionality. If a change is genuinely required in
  existing code, make the smallest one that works and say so.
- If something in these instructions conflicts with how the application is
  built, follow the application and explain the deviation.

## Final Verification

Before you report the work as done:

1. Re-read the acceptance criteria above and check each one against what you
   actually built.
2. Run the application and exercise the feature end to end.
3. Run the existing test suite and confirm you have broken nothing.
4. Check the feature on mobile, tablet, and desktop widths.
5. Check keyboard navigation and focus handling.
6. Summarize what changed: files added, files modified, and anything you
   deliberately did differently because of how this application is built.

If any acceptance criterion is unmet, fix it before reporting completion.