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/pyproject.toml

@@ -0,0 +1,65 @@
+[build-system]
+requires = ["hatchling"]
+build-backend = "hatchling.build"
+
+[project]
+name = "pipeline-core"
+version = "0.1.0"
+description = "Pipeline Core - Extensible multi-pipeline framework with dynamic dashboards"
+readme = "README.md"
+license = "MIT"
+requires-python = ">=3.11"
+authors = [
+    { name = "ReviewIQ Team" }
+]
+keywords = ["pipeline", "framework", "dashboard", "registry"]
+classifiers = [
+    "Development Status :: 3 - Alpha",
+    "Intended Audience :: Developers",
+    "License :: OSI Approved :: MIT License",
+    "Programming Language :: Python :: 3",
+    "Programming Language :: Python :: 3.11",
+    "Programming Language :: Python :: 3.12",
+]
+
+dependencies = [
+    "asyncpg>=0.28.0",
+    "pydantic>=2.0",
+    "pydantic-settings>=2.0",
+]
+
+[project.optional-dependencies]
+dev = [
+    "pytest>=7.0",
+    "pytest-asyncio>=0.21.0",
+    "pytest-cov>=4.0",
+    "ruff>=0.1.0",
+    "mypy>=1.0",
+]
+
+[project.urls]
+Homepage = "https://github.com/reviewiq/pipeline-core"
+Documentation = "https://github.com/reviewiq/pipeline-core#readme"
+Repository = "https://github.com/reviewiq/pipeline-core"
+
+[tool.hatch.build.targets.wheel]
+packages = ["src/pipeline_core"]
+
+[tool.pytest.ini_options]
+asyncio_mode = "auto"
+testpaths = ["tests"]
+pythonpath = ["src"]
+
+[tool.ruff]
+line-length = 100
+target-version = "py311"
+
+[tool.ruff.lint]
+select = ["E", "F", "I", "N", "W", "UP"]
+ignore = ["E501"]
+
+[tool.mypy]
+python_version = "3.11"
+strict = true
+warn_return_any = true
+warn_unused_ignores = true