When devRoot pointed at a monorepo, discoverProjects scanned one level
deep and listed each workspace/package as a separate project. Now it
checks for monorepo markers (pnpm-workspace.yaml, lerna.json, turbo.json,
nx.json, rush.json, package.json workspaces) before scanning children.
If the root is a monorepo, it returns it as a single project entry.
- Add detectMonorepo() to bridge-service with support for 6 monorepo formats
- Add isMonorepo signal to ProjectDetectionSignals
- Update discoverProjects to short-circuit when root is a monorepo
- Show 'Monorepo' tag in project list UI
- Add 24 tests covering all monorepo detection scenarios