fix: preserve idempotency keys across command retries (AEG-V16-022)

Create one immutable request per user intent so retries forward the same key; preserve concurrency conflict handling and execution evidence.

frontend/src/shared/crud/tests/useOptimisticCommand.spec.ts

@@ -0,0 +1,30 @@
+import { describe, expect, it } from 'vitest'
+import { useOptimisticCommand } from '../useOptimisticCommand'
+
+describe('useOptimisticCommand', () => {
+  it('reuses one idempotency key when an intent is retried', async () => {
+    const keys: string[] = []
+    const command = useOptimisticCommand(async (_request, headers) => {
+      keys.push(headers['Idempotency-Key'])
+      return { data: { accepted: true } }
+    })
+    const request = command.createRequest({ name: 'update' }, 'etag-1')
+
+    await command.run(request)
+    await command.run(request)
+
+    expect(keys).toHaveLength(2)
+    expect(keys[0]).toBe(request.idempotencyKey)
+    expect(keys[1]).toBe(request.idempotencyKey)
+  })
+
+  it('surfaces a 412 conflict and clears pending state', async () => {
+    const command = useOptimisticCommand(async () => {
+      throw { response: { status: 412 } }
+    })
+
+    await expect(command.run(command.createRequest({ name: 'update' }))).rejects.toEqual({ response: { status: 412 } })
+    expect(command.conflict.value).toBe(true)
+    expect(command.pending.value).toBe(false)
+  })
+})

frontend/src/shared/crud/useOptimisticCommand.js

@@ -1,5 +1,5 @@
 import { ref } from 'vue';
-import { createIdempotencyKey } from '../commands/idempotency';
+import { createIdempotentCommand } from '../commands/idempotency';
 export function useOptimisticCommand(execute) {
     const pending = ref(false);
     const conflict = ref(false);
@@ -10,7 +10,7 @@ export function useOptimisticCommand(execute) {
         pending.value = true;
         conflict.value = false;
         try {
-            const headers = { 'Idempotency-Key': createIdempotencyKey() };
+            const headers = { 'Idempotency-Key': request.idempotencyKey };
             if (request.etag)
                 headers['If-Match'] = request.etag;
             const response = await execute(request, headers);
@@ -27,5 +27,8 @@ export function useOptimisticCommand(execute) {
             pending.value = false;
         }
     }
-    return { pending, conflict, lastCorrelationId, run };
+    function createRequest(payload, etag) {
+        return Object.freeze({ ...createIdempotentCommand(payload), etag });
+    }
+    return { pending, conflict, lastCorrelationId, createRequest, run };
 }

frontend/src/shared/crud/useOptimisticCommand.ts

@@ -1,6 +1,6 @@
 import { ref } from 'vue'
-import { createIdempotencyKey } from '../commands/idempotency'
-export interface OptimisticCommandRequest<T> { payload: T; etag?: string }
+import { createIdempotentCommand, type IdempotentCommand } from '../commands/idempotency'
+export interface OptimisticCommandRequest<T> extends IdempotentCommand<T> { etag?: string }
 export interface OptimisticCommandResponse<TResult> { data: TResult; etag?: string; correlationId?: string }
 export function useOptimisticCommand<TPayload, TResult>(execute: (request: OptimisticCommandRequest<TPayload>, headers: Record<string,string>) => Promise<OptimisticCommandResponse<TResult>>) {
   const pending = ref(false); const conflict = ref(false); const lastCorrelationId = ref<string>()
@@ -8,7 +8,7 @@ export function useOptimisticCommand<TPayload, TResult>(execute: (request: Optim
     if (pending.value) throw new Error('Command is already in progress')
     pending.value=true; conflict.value=false
     try {
-      const headers: Record<string,string> = { 'Idempotency-Key': createIdempotencyKey() }
+      const headers: Record<string,string> = { 'Idempotency-Key': request.idempotencyKey }
       if (request.etag) headers['If-Match']=request.etag
       const response=await execute(request,headers); lastCorrelationId.value=response.correlationId; return response
     } catch (error: unknown) {
@@ -17,5 +17,8 @@ export function useOptimisticCommand<TPayload, TResult>(execute: (request: Optim
       throw error
     } finally { pending.value=false }
   }
-  return { pending, conflict, lastCorrelationId, run }
+  function createRequest(payload: TPayload, etag?: string): OptimisticCommandRequest<TPayload> {
+    return Object.freeze({ ...createIdempotentCommand(payload), etag })
+  }
+  return { pending, conflict, lastCorrelationId, createRequest, run }
 }