Workspace dropdown shows repos inaccessible to current account

### Description

The workspace/repo dropdown shows all configured repositories regardless of which GitHub account is currently active. Repos that are private to a different account should not appear in the list when they are inaccessible under the current account.

### Steps to Reproduce

1. Log in with multiple GitHub accounts via gh CLI
2. Add repos from different accounts to workspaces
3. Switch to an account that only has access to some of those repos
4. Open the workspace dropdown - all repos still appear, including ones the current account cannot access

### Expected Behavior

Workspace dropdown should only show repos accessible to the currently active GitHub account. Inaccessible repos should be hidden or visually marked as unavailable.

### Actual Behavior

All repos from all accounts are shown regardless of which account is active, leading to errors when selecting a repo the current account cannot access.

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Related: #4 - same domain around account switching not properly refreshing state.