KurrentDB.Projections.Management

Top-level orchestration layer for the projections subsystem.

Responsibilities

Lifecycle management — Creating, enabling, disabling, stopping, deleting, and resetting projections via the ManagedProjection state machine.
APIs — gRPC and HTTP endpoints for all projection operations (create, update, delete, statistics, state/result queries).
Subsystem coordination — ProjectionsSubsystem manages startup/shutdown and leader election awareness (projections only run on the leader node).
Projection registry — ProjectionManager maintains the registry of all active projections and dispatches commands to them.
Worker distribution — ProjectionCoreCoordinator manages multiple projection worker threads; ProjectionWorkerNode sets up individual workers.
Engine selection — ProcessingStrategySelector chooses between V1 and V2 engines per projection.
Prelude — Serves the JavaScript projection API files (Prelude/) over HTTP for the web editor.

Class	Purpose
`ProjectionsSubsystem`	Plugin/subsystem entry point, lifecycle, metrics
`ProjectionManager`	Central request dispatcher and projection registry
`ManagedProjection`	Wraps an individual projection with a state machine
`ProjectionCoreCoordinator`	Coordinates multiple projection core workers
`ProjectionCoreService`	Per-worker projection processing service
`ProcessingStrategySelector`	Selects V1 or V2 engine per projection
`ProjectionManagement` (gRPC)	gRPC service implementation
`ProjectionsController` (HTTP)	HTTP controller for REST/legacy clients

Management ──→ V1 ──→ Shared
    │                   ↑
    ├──→ V2 ────────────┘
    └──→ JavaScript

Management directly references V1, V2, and JavaScript. V1, V2, and JavaScript have no cross-dependencies — each depends only on Shared.