This commit introduces a protocol-based metrics architecture that allows
each module to provide its own statistics for dashboards without creating
cross-module dependencies.
Key changes:
- Add MetricsProviderProtocol and MetricValue dataclass in contracts module
- Add StatsAggregatorService in core module that discovers and aggregates
metrics from all enabled modules
- Implement metrics providers for all modules:
- tenancy: vendor/user counts, team members, domains
- customers: customer counts
- cms: pages, media files
- catalog: products
- inventory: stock levels
- orders: order counts, revenue
- marketplace: import jobs, staging products
- Update dashboard routes to use StatsAggregator instead of direct imports
- Fix VendorPlatform junction table usage (Vendor.platform_id doesn't exist)
- Add comprehensive documentation for the pattern
This architecture ensures:
- Dashboards always work (aggregator in core)
- Each module owns its metrics (no cross-module coupling)
- Optional modules are truly optional (can be removed without breaking app)
- Multi-platform vendors are properly supported via VendorPlatform table
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>