fix(calibration): observe WizardViewModel directly in CalibrationView

The Milestone 6 calibration UI test could not find `btnCreateLayout` because
`CalibrationView` only bound `CalibrationViewModel`. Its `canGenerate`
computed property reads `wizard.basename` and `wizard.effectiveWorkingDirectory`,
but those nested `WizardViewModel` changes were not propagated through
`TargetWorkflowViewModel` to the view, so the generate/layout buttons stayed
disabled after Stage 1 completed.

Changes:
- Add a `@Bindable var wizard: WizardViewModel` to `CalibrationView`.
- Pass `workflow.wizard` from `WizardStageContent` into `CalibrationView`.
- Replace `.disabled(!model.canGenerate)` with direct reads of
  `wizard.basename`, `wizard.effectiveWorkingDirectory`, and `model.isGenerating`
  so SwiftUI observes the wizard state directly and the buttons enable correctly.

Fixes the CI failure in
`Milestone6CalibrationUITests.testCalibrationDashboardOpensAndCanGenerate`.

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

Sources/ICCery/CalibrationView.swift

@@ -4,6 +4,7 @@ import ICCeryCore
 /// Stage 0 calibration dashboard (issue #29, docs/07).
 struct CalibrationView: View {
     @Bindable var model: CalibrationViewModel
+    @Bindable var wizard: WizardViewModel
 
     var body: some View {
         VStack(alignment: .leading, spacing: 0) {
@@ -51,11 +52,15 @@ struct CalibrationView: View {
                     HStack(spacing: 12) {
                         Button("Generate Target") { model.generateTarget() }
                             .accessibilityIdentifier("btnCalGenerate")
-                            .disabled(!model.canGenerate)
+                            .disabled(wizard.basename.isEmpty
+                                      || wizard.effectiveWorkingDirectory == nil
+                                      || model.isGenerating)
 
                         Button("Create Layout & Print") { model.createLayout() }
                             .accessibilityIdentifier("btnCalLayout")
-                            .disabled(!model.canGenerate)
+                            .disabled(wizard.basename.isEmpty
+                                      || wizard.effectiveWorkingDirectory == nil
+                                      || model.isGenerating)
 
                         Button("Measure") { model.measureChart() }
                             .accessibilityIdentifier("btnCalMeasure")

Sources/ICCery/RootView.swift

@@ -83,7 +83,7 @@ private struct WizardStageContent: View {
         case .verifyInstall:
             Stage5View(model: workflow.profile)
         case .calibrate:
-            CalibrationView(model: workflow.calibration)
+            CalibrationView(model: workflow.calibration, wizard: workflow.wizard)
         @unknown default:
             StagePlaceholderView(stage: model.stage)
         }