Bound each provider's startFetch()/resolveFetch() to an optional
since/until window, wire a SQLite-backed ContributionStore into
ContributionAggregator (fetch only the trailing window past the last
stored date, merge into the store, prune by CONTRIBUTIONS_RETENTION_DAYS),
and add a graph:contributions:refetch command to force a full or ranged
re-fetch in <=365-day chunks. This is the root fix for the full
365-day-refetch timeout that used to hit on every cache miss.
Move all provider-related classes, enums, interface and trait into
App\Service\Provider; move SvgRenderer into App\Service\Renderer.
ContributionAggregator stays at the Service root as the orchestrator.
Test namespaces and use statements updated to match.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>