Fix typos detected by nightly scan (#980)

- docs/user-guide/LeaderWorkerSet-support.md: shoud -> should
- internal/engines/analyzers/queueingmodel/tuner/utils.go: expextedObservations -> expectedObservations (4 occurrences)

Note: PNGs in test/benchmark/config.go is correct (plural of PNG), not a typo.

Closes #972

Author: jia-gao

docs/user-guide/LeaderWorkerSet-support.md

@@ -28,7 +28,7 @@ There's no additional configuration needed in WVA controller to enable LWS suppo
 ```
 2026-03-21T09:02:09-04:00	INFO	setup	cmd/main.go:202	LeaderWorkerSet CRD detected - support enabled
 ```
-Otherwise, the log shoud contain:
+Otherwise, the log should contain:
 ```
 2026-03-21T09:13:31-04:00	INFO	setup	cmd/main.go:204	LeaderWorkerSet CRD not found - support disabled (Deployment-only mode)
 

internal/engines/analyzers/queueingmodel/tuner/utils.go

@@ -91,11 +91,11 @@ func CreateTunerConfigFromData(filterDataFromConfig *FilterData, env *Environmen
 
 	// Expected observations [TTFT, ITL] in milliseconds
 	// Use actual observations from environment if valid, otherwise use typical values
-	var expextedObservations []float64
+	var expectedObservations []float64
 	if env != nil && env.Valid() {
-		expextedObservations = []float64{float64(env.AvgTTFT), float64(env.AvgITL)}
+		expectedObservations = []float64{float64(env.AvgTTFT), float64(env.AvgITL)}
 	} else {
-		expextedObservations = []float64{DefaultExpectedTTFT, DefaultExpectedITL}
+		expectedObservations = []float64{DefaultExpectedTTFT, DefaultExpectedITL}
 	}
 
 	return &TunerConfigData{
@@ -107,7 +107,7 @@ func CreateTunerConfigFromData(filterDataFromConfig *FilterData, env *Environmen
 			BoundedState:         true,
 			MinState:             minState,
 			MaxState:             maxState,
-			ExpectedObservations: expextedObservations,
+			ExpectedObservations: expectedObservations,
 		},
 	}
 }