test(performance): add end-to-end Xtream benchmark harness (#1300)

* docs(performance): plan Xtream benchmark

* feat(xtream-mock-server): add deterministic 100k fixture

* style(xtream-mock-server): apply repository formatting

* fix(xtream-mock-server): harden performance fixture data

* feat(xtream-mock-server): add performance control plane

* docs(performance): correct Xtream capture plan

* fix(xtream-mock-server): harden performance controls

* fix(xtream-mock-server): harden control lifecycle

* feat(performance): add Xtream preload markers

* feat(performance): trace Xtream main phases

* feat(performance): mark Xtream store publications

* feat(performance): trace Xtream database phases

* feat(performance): trace Xtream delete cancellation

* feat(performance): capture Xtream phase attribution

* feat(performance): mark Sources Xtream refresh

* test(performance): define Xtream benchmark evidence contracts

* test(performance): add Xtream benchmark runner

* test(performance): surface failure evidence writes

* test(performance): align database read clock

* test(performance): preserve capture failure contracts

apps/electron-backend-e2e/src/performance/worker-request-performance.ts

@@ -152,7 +152,8 @@ function parseEventLoopDelay(
 
 function parseWorkerPerformanceCapture(
     input: unknown,
-    operation: string | null
+    operation: string | null,
+    requestSucceeded: boolean
 ): ParsedWorkerPerformanceCapture | null {
     if (!isRecord(input)) {
         return null;
@@ -203,7 +204,8 @@ function parseWorkerPerformanceCapture(
         operation,
         input['phaseEvents'],
         workStartedEpochMs,
-        workEndedEpochMs
+        workEndedEpochMs,
+        requestSucceeded
     );
     if (phaseEvents === null) {
         return null;
@@ -318,7 +320,8 @@ export function normalizeWorkerRequestPerformanceOutcome(
 
     const performanceCapture = parseWorkerPerformanceCapture(
         input.performanceCapture,
-        input.operation
+        input.operation,
+        input.success
     );
     if (!performanceCapture) {
         return unavailable('worker-performance-capture-invalid');