feat(gatekeeper): add PR merge automation service

docs/scratchpads/90-event-subscriptions-summary.md

@@ -12,6 +12,7 @@ Successfully implemented EVENT message type for federation, enabling pub/sub eve
 ## What Was Implemented
 
 ### Database Schema
+
 - **FederationEventSubscription Model**: New table for storing event subscriptions
   - Fields: id, workspaceId, connectionId, eventType, metadata, isActive, timestamps
   - Unique constraint on (workspaceId, connectionId, eventType)
@@ -21,6 +22,7 @@ Successfully implemented EVENT message type for federation, enabling pub/sub eve
 ### Core Services
 
 **EventService** (`event.service.ts`)
+
 - `subscribeToEventType()`: Subscribe to events from remote instance
 - `unsubscribeFromEventType()`: Remove event subscription
 - `publishEvent()`: Publish events to all subscribed connections
@@ -35,6 +37,7 @@ Successfully implemented EVENT message type for federation, enabling pub/sub eve
 **EventController** (`event.controller.ts`)
 
 **Authenticated Endpoints (require AuthGuard):**
+
 - `POST /api/v1/federation/events/subscribe` - Subscribe to event type
 - `POST /api/v1/federation/events/unsubscribe` - Unsubscribe from event type
 - `POST /api/v1/federation/events/publish` - Publish event to subscribers
@@ -43,12 +46,14 @@ Successfully implemented EVENT message type for federation, enabling pub/sub eve
 - `GET /api/v1/federation/events/messages/:id` - Get single event message
 
 **Public Endpoints (signature-verified):**
+
 - `POST /api/v1/federation/incoming/event` - Receive event from remote instance
 - `POST /api/v1/federation/incoming/event/ack` - Receive event acknowledgment
 
 ### Type Definitions
 
 **Added to `message.types.ts`:**
+
 - `EventMessage`: Outgoing event structure
 - `EventAck`: Event acknowledgment structure
 - `EventMessageDetails`: Event message response type
@@ -57,6 +62,7 @@ Successfully implemented EVENT message type for federation, enabling pub/sub eve
 ### Data Transfer Objects
 
 **event.dto.ts:**
+
 - `SubscribeToEventDto`: Subscribe request
 - `UnsubscribeFromEventDto`: Unsubscribe request
 - `PublishEventDto`: Publish event request
@@ -66,12 +72,14 @@ Successfully implemented EVENT message type for federation, enabling pub/sub eve
 ## Testing
 
 ### Test Coverage
+
 - **EventService**: 18 unit tests, **89.09% coverage** ✅
 - **EventController**: 11 unit tests, **83.87% coverage** ✅
 - **Total**: 29 tests, all passing
 - **Coverage**: Exceeds 85% minimum requirement
 
 ### Test Scenarios Covered
+
 - Subscription creation and deletion
 - Event publishing to multiple subscribers
 - Failed delivery handling
@@ -84,17 +92,21 @@ Successfully implemented EVENT message type for federation, enabling pub/sub eve
 ## Design Patterns
 
 ### Consistency with Existing Code
+
 - Follows patterns from `QueryService` and `CommandService`
 - Reuses existing `SignatureService` for message verification
 - Reuses existing `FederationService` for instance identity
 - Uses existing `FederationMessage` model with new `eventType` field
 
 ### Event Type Naming Convention
+
 Hierarchical dot-notation:
+
 - `entity.action` (e.g., "task.created", "user.updated")
 - `entity.action.detail` (e.g., "task.status.changed")
 
 ### Security Features
+
 - All events signature-verified (RSA)
 - Timestamp validation (prevents replay attacks)
 - Connection status validation (only active connections)
@@ -103,14 +115,18 @@ Hierarchical dot-notation:
 ## Technical Details
 
 ### Database Migration
+
 File: `20260203_add_federation_event_subscriptions/migration.sql`
+
 - Adds `eventType` column to `federation_messages`
 - Creates `federation_event_subscriptions` table
 - Adds appropriate indexes for performance
 - Establishes foreign key relationships
 
 ### Integration
+
 Updated `federation.module.ts`:
+
 - Added `EventService` to providers
 - Added `EventController` to controllers
 - Exported `EventService` for use by other modules
@@ -126,6 +142,7 @@ Updated `federation.module.ts`:
 ## Files Created/Modified
 
 ### New Files (7)
+
 - `apps/api/src/federation/event.service.ts` (470 lines)
 - `apps/api/src/federation/event.service.spec.ts` (1,088 lines)
 - `apps/api/src/federation/event.controller.ts` (199 lines)
@@ -135,11 +152,13 @@ Updated `federation.module.ts`:
 - `docs/scratchpads/90-event-subscriptions.md` (185 lines)
 
 ### Modified Files (3)
+
 - `apps/api/src/federation/types/message.types.ts` (+118 lines)
 - `apps/api/src/federation/federation.module.ts` (+3 lines)
 - `apps/api/prisma/schema.prisma` (+27 lines)
 
 ### Total Changes
+
 - **2,395 lines added**
 - **5 lines removed**
 - **10 files changed**
@@ -147,20 +166,25 @@ Updated `federation.module.ts`:
 ## Key Features
 
 ### Server-Side Event Filtering
+
 Events are only sent to instances with active subscriptions for that event type. This prevents unnecessary network traffic and processing.
 
 ### Acknowledgment Protocol
+
 Simple ACK pattern confirms event delivery:
+
 1. Publisher sends event
 2. Receiver processes and returns ACK
 3. Publisher updates delivery status
 
 ### Error Handling
+
 - Failed deliveries marked as FAILED with error message
 - Connection errors logged but don't crash the system
 - Invalid signatures rejected immediately
 
 ### Subscription Management
+
 - Subscriptions persist in database
 - Can be activated/deactivated without deletion
 - Support for metadata (extensibility)
@@ -168,6 +192,7 @@ Simple ACK pattern confirms event delivery:
 ## Future Enhancements (Not Implemented)
 
 These were considered but deferred to future issues:
+
 - Event replay/history
 - Event filtering by payload fields
 - Webhook support for event delivery
@@ -179,11 +204,13 @@ These were considered but deferred to future issues:
 ## Performance Considerations
 
 ### Scalability
+
 - Database indexes on eventType, connectionId, workspaceId
 - Efficient queries with proper WHERE clauses
 - Server-side filtering reduces network overhead
 
 ### Monitoring
+
 - All operations logged with appropriate level
 - Failed deliveries tracked in database
 - Delivery timestamps recorded for analytics
@@ -191,12 +218,14 @@ These were considered but deferred to future issues:
 ## Documentation
 
 ### Inline Documentation
+
 - JSDoc comments on all public methods
 - Clear parameter descriptions
 - Return type documentation
 - Usage examples in comments
 
 ### Scratchpad Documentation
+
 - Complete implementation plan
 - Design decisions documented
 - Testing strategy outlined
@@ -205,6 +234,7 @@ These were considered but deferred to future issues:
 ## Integration Testing Recommendations
 
 While unit tests are comprehensive, recommend integration testing:
+
 1. Set up two federated instances
 2. Subscribe from Instance A to Instance B events
 3. Publish event from Instance B
@@ -214,6 +244,7 @@ While unit tests are comprehensive, recommend integration testing:
 ## Conclusion
 
 FED-007 (EVENT Subscriptions) is **complete and ready for code review**. The implementation:
+
 - ✅ Follows TDD principles
 - ✅ Meets 85%+ code coverage requirement
 - ✅ Passes all quality gates (lint, typecheck, tests)