- Remove "Operator branch" and "Agent default" options from the workspace
mode dropdown in both NewIssueDialog and IssueProperties, keeping only
"Project default", "New isolated workspace", and "Reuse existing workspace"
- Deduplicate reusable workspaces by space identity (cwd path) so the
"choose existing workspace" dropdown shows unique worktrees instead of
duplicate entries from multiple issues sharing the same local folder
Co-Authored-By: Paperclip <noreply@paperclip.ing>