Migrate BrandDesignUpdatePageViewModel onto LinearOnboardingOrchestrator

[LukasPaczos]

Task/Issue URL: https://app.asana.com/1/137249556945/project/1208671518894266/task/1215622484916139?focus=true
Tech Design URL (if applicable): https://app.asana.com/1/137249556945/project/481882893211075/task/1214772963645835

Description

Stacked on #8840. This change moves the new-user linear onboarding flow onto that orchestrator, behind a kill switch, with no behaviour change.

It composes the new-user flow as a plan in NewUserOnboardingPlanProvider (the ordered steps, their preconditions, side effects, and the skip / quick-setup side plans), starts it from LaunchViewModel via NewUserOnboardingPlanBootstrapper, and routes BrandDesignUpdatePageViewModel through it. The page ViewModel picks one of two flow strategies at construction:

• OrchestratorFlow translates fragment callbacks into orchestrator events and renders the current step.
• LegacyFlow keeps the existing in-ViewModel state machine unchanged.

The linearOnboardingOrchestrator feature flag selects between them (enabled by default). Intra-dialog interactions (quick-setup rows, widgets, notification callbacks) stay in the ViewModel in both modes.

Pixels were verified to match across the base, skip, and skip-then-resume, quick-setup, and sync restore scenarios for three builds: the pre-change baseline, flag off, and flag on.

Steps to test this PR

Base flow via orchestrator

• Clean install
• Launch the app
• Go through linear onboarding
  • Verify all steps are present and transition correctly
• Reach the browser
  • Verify the in-context CTAs show

Skip->return flow via orchestrator

• Clean install
• Launch the app
• Click "I've been here before"
• Click "Show Tutorial"
  • Verify browser comparison step is shown
• Go through linear onboarding
  • Verify all steps are present and transition correctly.
• Reach the browser
  • Verify the in-context CTAs show

Skip flow via orchestrator

• Clean install
• Launch the app
• Click "I've been here before"
• Click "Start browsing"
• Reach the browser
  • Verify the native input box is visible and focused

Restore sync flow via orchestrator

• Enable sync on the device
• Uninstall the app (don't clear data)
• Launch the app
  • Verify you see the "Let's pick up where you left off" screen

Quick setup flow via orchestrator
Apply below diff:

diff --git a/app/src/main/java/com/duckduckgo/app/onboardingquicksetup/OnboardingQuickSetupExperimentManager.kt b/app/src/main/java/com/duckduckgo/app/onboardingquicksetup/OnboardingQuickSetupExperimentManager.kt
index b4ddba2126..a70907c829 100644
--- a/app/src/main/java/com/duckduckgo/app/onboardingquicksetup/OnboardingQuickSetupExperimentManager.kt
+++ b/app/src/main/java/com/duckduckgo/app/onboardingquicksetup/OnboardingQuickSetupExperimentManager.kt
@@ -45,6 +45,7 @@ class OnboardingQuickSetupExperimentManagerImpl @Inject constructor(
 ) : OnboardingQuickSetupExperimentManager {
 
     override suspend fun enroll(): QuickSetupExperimentVariant? = withContext(dispatcherProvider.io()) {
+        return@withContext QuickSetupExperimentVariant.TREATMENT
         toggles.onboardingQuickSetupExperimentJun3().enroll()
         when {
             toggles.onboardingQuickSetupExperimentJun3().isEnrolledAndEnabled(QuickSetupCohorts.TREATMENT) -> {

• Clear data (to get rid of sync restore)
• Launch the app
• Click "I've been here before"
  • Verify Quick setup page is visible
• Change address bar position to bottom and start browsing
  • Verify the bottom option is applied

Apply below diff:

diff --git a/app/src/main/java/com/duckduckgo/app/onboarding/LinearOnboardingOrchestratorFeature.kt b/app/src/main/java/com/duckduckgo/app/onboarding/LinearOnboardingOrchestratorFeature.kt
index 89716bbfda..1eb455e745 100644
--- a/app/src/main/java/com/duckduckgo/app/onboarding/LinearOnboardingOrchestratorFeature.kt
+++ b/app/src/main/java/com/duckduckgo/app/onboarding/LinearOnboardingOrchestratorFeature.kt
@@ -31,6 +31,6 @@ import com.duckduckgo.feature.toggles.api.Toggle.DefaultFeatureValue
     featureName = "linearOnboardingOrchestrator",
 )
 interface LinearOnboardingOrchestratorFeature {
-    @Toggle.DefaultValue(DefaultFeatureValue.TRUE)
+    @Toggle.DefaultValue(DefaultFeatureValue.FALSE)
     fun self(): Toggle
 }

Base flow via VM

• Clean install
• Launch the app
• Go through linear onboarding
  • Verify all steps are present and transition correctly
• Reach the browser
  • Verify the in-context CTAs show

Skip->return flow via VM

• Clean install
• Launch the app
• Click "I've been here before"
• Click "Show Tutorial"
  • Verify browser comparison step is shown
• Go through linear onboarding
  • Verify all steps are present and transition correctly.
• Reach the browser
  • Verify the in-context CTAs show

Skip flow via VM

• Clean install
• Launch the app
• Click "I've been here before"
• Click "Start browsing"
• Reach the browser
  • Verify the native input box is visible and focused

Restore sync flow via VM

• Enable sync on the device
• Uninstall the app (don't clear data)
• Launch the app
  • Verify you see the "Let's pick up where you left off" screen

Quick setup flow via VM
Apply below diff:

diff --git a/app/src/main/java/com/duckduckgo/app/onboardingquicksetup/OnboardingQuickSetupExperimentManager.kt b/app/src/main/java/com/duckduckgo/app/onboardingquicksetup/OnboardingQuickSetupExperimentManager.kt
index b4ddba2126..a70907c829 100644
--- a/app/src/main/java/com/duckduckgo/app/onboardingquicksetup/OnboardingQuickSetupExperimentManager.kt
+++ b/app/src/main/java/com/duckduckgo/app/onboardingquicksetup/OnboardingQuickSetupExperimentManager.kt
@@ -45,6 +45,7 @@ class OnboardingQuickSetupExperimentManagerImpl @Inject constructor(
 ) : OnboardingQuickSetupExperimentManager {
 
     override suspend fun enroll(): QuickSetupExperimentVariant? = withContext(dispatcherProvider.io()) {
+        return@withContext QuickSetupExperimentVariant.TREATMENT
         toggles.onboardingQuickSetupExperimentJun3().enroll()
         when {
             toggles.onboardingQuickSetupExperimentJun3().isEnrolledAndEnabled(QuickSetupCohorts.TREATMENT) -> {

• Clear data (to get rid of sync restore)
• Launch the app
• Click "I've been here before"
  • Verify Quick setup page is visible
• Change address bar position to bottom and start browsing
  • Verify the bottom option is applied

UI changes

No changes expected.

---

Note

Medium Risk
First-run onboarding is a critical path with a large dual-path refactor; rollback relies on the remote flag, and orchestrator mode intentionally differs from legacy in at least one default-browser edge case covered by tests.

Overview
New-user onboarding is wired to the shared LinearOnboardingOrchestrator behind remote toggle linearOnboardingOrchestrator (on by default). When enabled, LaunchViewModel starts the run via NewUserOnboardingPlanBootstrapper before opening OnboardingActivity; when disabled, behavior stays on the existing in-VM flow.

The PR adds NewUserOnboardingPlanProvider, which defines the full linear plan (intro, notifications, sync restore / reinstall / initial forks, comparison chart, default browser, address bar, input mode + preview, skip and quick-setup side plans), step events, pixels, and completion results (launch search/chat). BrandDesignUpdatePageViewModel picks OrchestratorFlow or LegacyFlow at construction: orchestrator mode maps UI callbacks to events and renders resolveDialog() output; legacy mode keeps the prior state machine unchanged.

OnboardingViewModel and OnboardingActivity defer terminal AppStage / skip writes and dev-skip navigation when the orchestrator is driving the run. onboarding-api / onboarding-impl are added as app dependencies; lint baselines record temporary *-impl imports in tests and orchestrator code.

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[LukasPaczos]

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[catalinradoiu]

Looks good and works as expected! 👍

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