fix: register platform.region_router factory and add missing type registry entries

- Add Init() method to MultiRegionRoutingModule to satisfy modular.Module interface
- Register platform.region_router factory in platform plugin ModuleFactories()
- Add ~15 missing module types to KnownModuleTypes(): nosql.memory/dynamodb/mongodb/redis,
  storage.artifact, cloud.account, gitlab.client/webhook, aws.codebuild,
  policy.opa/cedar/mock, tracing.propagation, platform.region_router/doks/do_networking/do_dns/do_app
- Add ~50 missing step types to KnownStepTypes(): nosql, artifact, cloud, build_binary,
  codebuild, gitlab, policy, tracing, marketplace, region, argo, digitalocean steps
- Add reconciliation to KnownTriggerTypes()

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: intel352