feat(ui): Create content pattern components - DataTable, FilterBar, EmptyState, LoadingState

- Add LoadingState with table, card, list, and text skeleton patterns
- Add EmptyState with customizable icon, title, description, and action slot
- Add FilterBar with search input, clear button, and custom filter slot
- Add DataTable with TanStack Table integration, sorting, and row click
- Create barrel export index.ts for common components
- Install tanstack-table-8-svelte-5 for Svelte 5 compatibility
- Sync auth spec with authenticated user redirect requirements
- Archive p03-dashboard-enhancement

Refs: openspec/changes/p04-content-patterns
Closes: p04-content-patterns

openspec/changes/archive/2026-02-18-p03-dashboard-enhancement/proposal.md

@@ -0,0 +1,60 @@
+# Proposal: Dashboard Enhancement
+
+## Overview
+Transform the dashboard page into a data-rich overview with KPI stat cards and allocation preview, using the new layout components.
+
+## Goals
+- Create PageHeader component for consistent page titles
+- Create StatCard component for KPI display
+- Enhance dashboard with team/project/ utilization KPIs
+- Add quick links to common actions
+- Polish login page for consistency
+
+## Non-Goals
+- Allocation matrix component (done in p04)
+- Other page implementations (done in p05)
+
+## Priority
+**MEDIUM** - First "real" page using new layout
+
+## Scope
+
+### PageHeader Component
+- Page title
+- Optional description
+- Action buttons slot
+- Consistent styling
+
+### StatCard Component
+- Value display
+- Label
+- Trend indicator (up/down)
+- Icon support
+- DaisyUI stat styling
+
+### Dashboard Enhancement
+- Row of 4 stat cards (Active Projects, Team Members, Current Month Allocations, Avg Utilization)
+- Quick actions section
+- Recent activity placeholder
+
+### Login Polish
+- Center card vertically
+- Add app logo/branding
+- Improve form styling
+
+## Success Criteria
+- [ ] PageHeader component created
+- [ ] StatCard component created
+- [ ] Dashboard shows 4 KPI cards
+- [ ] Login page polished
+- [ ] All tests pass
+
+## Estimated Effort
+2-3 hours
+
+## Dependencies
+- p02-app-layout
+
+## Blocks
+- p04-content-patterns (can start in parallel)
+- p05-page-migrations