Phases 5-7: Dashboard UI, Admin API, and Auth middleware

Phase 5 - Main Dashboard:
- Dashboard overview page with system health stats
- Jobs by status breakdown, success rates, top clients
- Dashboard API (/api/dashboard/overview, by-client, problems, by-version)

Phase 6 - Admin/Scraper Management:
- Scrapers management page with traffic allocation UI
- Admin API for scraper CRUD operations
- Traffic percentage updates for A/B testing
- Promote/deprecate scraper versions

Phase 7 - Authentication:
- API key authentication middleware
- SHA-256 key hashing (keys never stored in plain text)
- Scope-based authorization (jobs:read, jobs:write, admin)
- Rate limiting per API key

Also:
- Updated api_server_production.py to include new routers
- Extended core/database.py with dashboard query methods
- Added dashboard link to sidebar navigation
- Updated CONTEXT-KEEPER.md to mark all phases complete

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

api/middleware/__init__.py

@@ -0,0 +1,22 @@
+#!/usr/bin/env python3
+"""
+API Middleware for ReviewIQ.
+
+This module exports authentication and other middleware components.
+"""
+
+from api.middleware.auth import (
+    APIKeyAuth,
+    api_key_header,
+    generate_api_key,
+    create_auth,
+    AVAILABLE_SCOPES,
+)
+
+__all__ = [
+    "APIKeyAuth",
+    "api_key_header",
+    "generate_api_key",
+    "create_auth",
+    "AVAILABLE_SCOPES",
+]