## Context
This commit adds the supporting infrastructure that makes the assign
feature work end-to-end.
## Components Added/Modified
### SmartDag
- Main view component for graph-based task management
- Integrates TaskCardGrid and WorkflowGraph
- Has 'Assign' mode toggle button
- Passes archetypes and assignMode to WorkflowGraph
- Manages filter state (hideClosed, sortReadyFirst, etc.)
### useGraphAnalysis Hook
- Extracted graph analysis logic for reuse
- Returns: actionableNodeIds, cycleNodeIdSet, blockerTooltipMap, etc.
- Used by both SmartDag and AssignmentPanel
- Ensures consistent 'actionable' definition across components
### UnifiedShell
- Added assignMode state
- Added selectedAssignIssue state
- Renders AssignmentPanel when in graph view + assign mode
- Wires up onAssignModeChange and onSelectedIssueChange callbacks
## Design Philosophy
- Shared hook means single source of truth for 'actionable'
- Clean separation between view (SmartDag) and sidebar (AssignmentPanel)
- URL state preserved for navigation
## Test Coverage
- SmartDag tests: 12 tests covering buttons, callbacks, imports
- useGraphAnalysis tests: 6 tests covering cycle detection, blockers
- UnifiedShell tests: 9 tests covering state and rendering
STORY:
Phase 1 of the Unified UX epic required a complete 3-panel shell layout
with responsive behavior across mobile, tablet, and desktop breakpoints.
The existing page structure was fragmented - we needed a cohesive shell.
COLLABORATION:
Three agents (bb-5am, bb-dwz, bb-3dv) worked in parallel on:
- TopBar: View tabs (Social/Graph/Swarm) with active states, filter input
- LeftPanel: Channel tree navigation with epic filtering, responsive collapse
- RightPanel: Detail strip with sidebar (desktop) / drawer (tablet/mobile) modes
We encountered a hydration mismatch error on mobile/tablet because
useResponsive was returning different values on server vs client.
Fixed by defaulting to desktop on server and only updating after mount.
Mobile navigation (bb-ui2.27) added:
- Hamburger menu for left panel access on mobile/tablet
- Bottom tab bar for thumb-friendly view switching
DELIVERABLES:
- src/components/shared/top-bar.tsx: TopBar with view tabs + hamburger
- src/components/shared/left-panel.tsx: Epic tree with expand/collapse
- src/components/shared/right-panel.tsx: Responsive sidebar/drawer
- src/components/shared/unified-shell.tsx: Main 3-panel grid layout
- src/components/shared/mobile-nav.tsx: Bottom tab bar for mobile
- src/hooks/use-responsive.ts: Breakpoint detection (mobile/tablet/desktop)
- Tests for all components
VERIFICATION:
- npm run typecheck: PASS
- npm run lint: PASS
- npm run test: PASS
CLOSES: bb-ui2.6, bb-ui2.7, bb-ui2.8, bb-ui2.9, bb-ui2.27
