When a user tries to drag a card from backlog to in_progress while at the
max concurrency limit, a toast notification now appears explaining why the
action was blocked and suggesting solutions.
- Added sonner toast library
- Show error toast with dynamic message based on max concurrency
- Updated test utilities with toast helpers
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Added maxConcurrency state to app-store with persistence
- Created slider UI component using Radix UI
- Added concurrency slider to board-view header (left of Auto Mode button)
- Updated use-auto-mode hook to expose canStartNewTask based on limit
- Block dragging features to in_progress when at max concurrency
- Added test utilities for concurrency slider interactions
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
