feat: Add extensible multi-pipeline integration system

This commit implements a plugin-like pipeline architecture with:

Pipeline Core Package (packages/pipeline-core/):
- BasePipeline abstract class all pipelines implement
- PipelineRegistry for database-backed discovery/management
- PipelineRunner for execution with status tracking
- DashboardConfig contracts for dynamic widget definitions

Database Migration (006_pipeline_registry.sql):
- pipeline.registry table for registered pipelines
- pipeline.executions table for execution history
- Views for execution stats and monitoring

ReviewIQ Pipeline Refactor:
- Implements BasePipeline interface
- Adds get_dashboard_config() with widget definitions
- Adds get_widget_data() methods for all dashboard widgets
- Maintains backward compatibility with Pipeline alias

Generic Pipeline API (api/routes/pipelines.py):
- GET /api/pipelines - List all registered pipelines
- GET /api/pipelines/{id} - Pipeline details
- POST /api/pipelines/{id}/execute - Execute pipeline
- GET /api/pipelines/{id}/dashboard - Dashboard config
- GET /api/pipelines/{id}/widgets/{w} - Widget data
- GET /api/pipelines/{id}/executions - Execution history

Frontend Dynamic Dashboard System:
- DynamicDashboard component renders from config
- WidgetRegistry maps types to components
- Widget components: StatCard, LineChart, BarChart,
  PieChart, DataTable, Heatmap
- Pipeline API client library

Frontend Pipeline Pages:
- /pipelines - List all registered pipelines
- /pipelines/[id] - Dynamic dashboard for pipeline
- /pipelines/[id]/executions - Execution history
- Pipelines nav item in Sidebar

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

web/components/dashboard/index.ts

@@ -0,0 +1,26 @@
+/**
+ * Dashboard component exports.
+ *
+ * This module provides the dynamic dashboard system that renders
+ * pipeline dashboards from configuration.
+ */
+
+// Main components
+export { DynamicDashboard } from './DynamicDashboard';
+export { DashboardSection } from './DashboardSection';
+
+// Widget registry
+export {
+  getWidgetComponent,
+  isWidgetTypeSupported,
+  renderWidget,
+} from './WidgetRegistry';
+
+// Individual widgets
+export { StatCard } from './widgets/StatCard';
+export { LineChartWidget } from './widgets/LineChart';
+export { BarChartWidget } from './widgets/BarChart';
+export { PieChartWidget } from './widgets/PieChart';
+export { DataTableWidget } from './widgets/DataTable';
+export { HeatmapWidget } from './widgets/Heatmap';
+export { WidgetWrapper } from './widgets/WidgetWrapper';