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>

packages/pipeline-core/README.md

@@ -0,0 +1,119 @@
+# Pipeline Core
+
+Extensible multi-pipeline framework with dynamic dashboards.
+
+## Overview
+
+Pipeline Core provides the base abstractions for building pipelines that can be:
+- Discovered and registered dynamically
+- Executed with status tracking
+- Rendered with auto-generated dashboards
+
+## Features
+
+- **BasePipeline** - Abstract base class all pipelines implement
+- **PipelineRegistry** - Database-backed pipeline discovery and management
+- **PipelineRunner** - Execution with status tracking
+- **Dashboard Contracts** - TypedDicts for widget configuration
+
+## Installation
+
+```bash
+pip install -e packages/pipeline-core
+```
+
+## Usage
+
+### Implementing a Pipeline
+
+```python
+from pipeline_core import BasePipeline, PipelineMetadata, DashboardConfig
+
+class MyPipeline(BasePipeline):
+    @property
+    def metadata(self) -> PipelineMetadata:
+        return {
+            "id": "my-pipeline",
+            "name": "My Pipeline",
+            "description": "Does something useful",
+            "version": "1.0.0",
+            "stages": ["stage1", "stage2"],
+            "input_type": "MyInputType",
+        }
+
+    async def initialize(self) -> None:
+        # Set up connections
+        pass
+
+    async def close(self) -> None:
+        # Clean up
+        pass
+
+    async def process(self, input_data, stages=None):
+        # Run the pipeline
+        pass
+
+    def get_dashboard_config(self) -> DashboardConfig:
+        return {
+            "pipeline_id": "my-pipeline",
+            "title": "My Dashboard",
+            "sections": [...]
+        }
+
+    async def get_widget_data(self, widget_id, params):
+        # Return widget data
+        pass
+```
+
+### Registering a Pipeline
+
+```python
+from pipeline_core import PipelineRegistry
+import asyncpg
+
+pool = await asyncpg.create_pool(database_url)
+registry = PipelineRegistry(pool)
+
+await registry.register(
+    pipeline_id="my-pipeline",
+    name="My Pipeline",
+    description="Does something useful",
+    version="1.0.0",
+    module_path="my_package.pipeline:MyPipeline",
+    stages=["stage1", "stage2"],
+    input_type="MyInputType",
+)
+```
+
+### Executing a Pipeline
+
+```python
+from pipeline_core import PipelineRunner
+
+runner = PipelineRunner(pool, registry)
+
+execution_id, result = await runner.execute(
+    pipeline_id="my-pipeline",
+    request={
+        "input_data": {"key": "value"},
+        "stages": ["stage1"],
+    }
+)
+```
+
+## Dashboard Widgets
+
+Pipelines declare dashboard widgets via `get_dashboard_config()`. Available widget types:
+
+- `stat_card` - KPI stat card with value and trend
+- `line_chart` - Time series line chart
+- `bar_chart` - Bar chart (horizontal or vertical)
+- `pie_chart` - Pie/donut chart
+- `table` - Data table with columns
+- `heatmap` - Heatmap grid visualization
+- `area_chart` - Stacked area chart
+- `gauge` - Gauge/meter visualization
+
+## License
+
+MIT