feat: use shared_with_user filter for the shared workspaces view

[EhabY]

Summary

• The Shared Workspaces view now queries shared_with_user:<current user id> instead of fetching shared:true and filtering out own workspaces client-side. The server-side filter returns exactly the workspaces shared with the user, so excludeOwn/filterWorkspaces() are removed.
• When the server rejects the workspaces query with HTTP 400 (deployments older than 2.27.0), the view is hidden via a new coder.sharedWorkspacesSupported context key instead of showing an empty tree. The flag resets on any session change (login/logout/deployment switch) and on coder.refreshWorkspaces, so the view re-probes without restarting VS Code.
• Added initialSize weights to the sidebar views: My Workspaces 2, Shared 1, All 1 (50/25/25 when all are visible). Only affects fresh installs / reset layouts.

Compatibility

shared_with_user: shipped in the same server release as shared:true (both merged Sept 2025, first released in v2.27.0 — coder/coder#19807 and coder/coder#19875), so there is no deployment where the old query works and the new one doesn't. shared_with_user:me was intentionally avoided since "me" support only landed in coder/coder#26494 (v2.35+); the user UUID works on every supported version and is immune to renames.

On pre-2.27 deployments the previous behavior was a logged fetch error and a permanently empty Shared view; it is now hidden entirely.

Implementation plan / decision log

1. workspacesProvider.ts
   • WorkspaceQuery enum values become plain identifiers (mine/all/shared); the actual search query moves into WORKSPACE_QUERY_CONFIG as getQuery(session), built at fetch time because the Shared query needs the signed-in user's ID.
   • UUID over username: parseUser on the server accepts both, but the UUID avoids rename/quoting issues.
   • New onQueryRejected option, invoked only for axios HTTP 400 responses. Network errors/5xx keep the existing behavior (warning log + empty tree) so transient failures never hide the view.
2. extension.ts / contextManager.ts
   • New context key coder.sharedWorkspacesSupported, default true.
   • Shared provider sets it to false on onQueryRejected.
   • Reset to true on deploymentManager.session.onDidChange and in the coder.refreshWorkspaces command (covers in-place server upgrades: re-showing the view triggers its fetch, which hides it again if still unsupported). Hiding the view also stops its polling, since visibility drives the fetch loop.
3. package.json
   • sharedWorkspaces view gated on coder.authenticated && coder.sharedWorkspacesSupported (same pattern as coder.isOwner on allWorkspaces).
   • initialSize is a stable views-contribution property honored when the extension owns the view container (it does).
4. Tests: query expectations updated; the client-side ownership-filtering tests are replaced with onQueryRejected coverage (400 fires it once, non-400 does not).

Testing

• pnpm typecheck, pnpm lint, pnpm format:check
• pnpm test — 143 files, 2149 passed / 1 skipped

---

Generated by Coder Agents on behalf of @EhabY.