perf: dashboard revision-first 조회 계약을 추가

content revision과 별도인 source revision을 선택적으로 교환하고 coverage가 충족될 때만 payload loader를 생략한다. 구형 client와 미완성 producer coverage는 기존 full computation으로 안전하게 복구한다.

packages/common/src/realtime/delta.ts

@@ -11,16 +11,19 @@ export type ReadModelDelta<T> =
     | {
           kind: 'snapshot';
           revision: string;
+          sourceRevision?: string;
           data: T;
       }
     | {
           kind: 'unchanged';
           revision: string;
+          sourceRevision?: string;
       }
     | {
           kind: 'patch';
           baseRevision: string;
           revision: string;
+          sourceRevision?: string;
           operations: JsonPatchOperation[];
       };
 
@@ -41,6 +44,7 @@ export class ReadModelDeltaApplyError extends Error {
 export interface AppliedReadModelDelta<T> {
     data: T;
     revision: string;
+    sourceRevision?: string;
 }
 
 /**
@@ -143,6 +147,7 @@ export const applyReadModelDelta = <T>(
         return {
             data: delta.data,
             revision: delta.revision,
+            ...(delta.sourceRevision ? { sourceRevision: delta.sourceRevision } : {}),
         };
     }
 
@@ -159,6 +164,7 @@ export const applyReadModelDelta = <T>(
         return {
             data: current,
             revision: currentRevision,
+            ...(delta.sourceRevision ? { sourceRevision: delta.sourceRevision } : {}),
         };
     }
 
@@ -185,5 +191,6 @@ export const applyReadModelDelta = <T>(
     return {
         data: next,
         revision: delta.revision,
+        ...(delta.sourceRevision ? { sourceRevision: delta.sourceRevision } : {}),
     };
 };

packages/common/test/realtimeDelta.test.ts

@@ -118,6 +118,21 @@ describe('applyReadModelDelta', () => {
         expect(applied.data).toBe(current);
     });
 
+    it('carries an optional source revision without changing content revision semantics', () => {
+        const current = { value: 1 };
+        const applied = applyReadModelDelta(current, 'revision-1', {
+            kind: 'unchanged',
+            revision: 'revision-1',
+            sourceRevision: 'source-revision-2',
+        });
+
+        expect(applied).toEqual({
+            data: current,
+            revision: 'revision-1',
+            sourceRevision: 'source-revision-2',
+        });
+    });
+
     it('rejects a patch based on a different snapshot', () => {
         expect(() =>
             applyReadModelDelta({ value: 1 }, 'revision-2', {