fix(observability): tolerate missing report phase iteration

Author: j5ik2o

src/__tests__/engine-happy-path.test.ts

@@ -596,12 +596,12 @@ describe('WorkflowEngine Integration: Happy Path', () => {
           systemPrompt: expect.any(String),
           userInstruction: expect.any(String),
         }),
-        undefined,
+        'plan:1:1:1',
         1,
       );
       expect(phaseCompleteFn).toHaveBeenCalledWith(
         expect.objectContaining({ name: 'plan' }),
-        1, 'execute', expect.any(String), 'done', undefined, undefined, 1,
+        1, 'execute', expect.any(String), 'done', undefined, 'plan:1:1:1', 1,
       );
     });
 

src/__tests__/step-executor.test.ts

@@ -144,7 +144,7 @@ describe('StepExecutor', () => {
         systemPrompt: 'system prompt',
         userInstruction: expect.stringContaining('Return exactly one fenced JSON block'),
       },
-      undefined,
+      'implement:3:1:1',
       3,
     );
     expect(onPhaseStart).not.toHaveBeenCalledWith(

src/core/workflow/report-phase-runner.ts

@@ -183,9 +183,9 @@ export async function runReportPhase(
   log.debug('Report phase complete', { step: step.name, filesGenerated: reportFiles.length });
 }
 
-function nextReportPhaseExecutionId(stepName: string, iteration: number | undefined, sequence: number): string {
+function nextReportPhaseExecutionId(stepName: string, iteration: number | undefined, sequence: number): string | undefined {
   if (iteration == null) {
-    throw new Error(`Missing iteration for report phase execution id: ${stepName}`);
+    return undefined;
   }
   return buildPhaseExecutionId({
     step: stepName,
@@ -213,7 +213,7 @@ async function runSingleReportAttempt(
   instruction: string,
   options: RunAgentOptions,
   ctx: PhaseRunnerContext,
-  phaseExecutionId: string,
+  phaseExecutionId: string | undefined,
 ): Promise<ReportAttemptResult> {
   let didEmitPhaseStart = false;
   let resolvedPromptParts: PhasePromptParts | undefined;