PIR: Add handling of GenerateEmail action

[landomen]

Task/Issue URL: https://app.asana.com/1/137249556945/project/481882893211075/task/1213993026941869?focus=true

Description

Adds logic for GenerateEmail action and refactors the implicit email handling to use same approach as the new explicit one.

Steps to test this PR

Will be testable later when feature is complete.

UI changes

No UI changes

---

Note

Medium Risk
Moderate risk because it changes PIR action sequencing and how generated emails are propagated into script request data, which can affect opt-out/email-confirmation flows and retries across multiple broker step types.

Overview
Adds first-class handling for BrokerAction.GenerateEmail: ExecuteBrokerStepActionEventHandler now requests email generation when encountering this action, and EmailReceivedEventHandler advances to the next action when the current action was GenerateEmail.

Refactors the legacy implicit needsEmail path to stop mutating profileToOptOut.email; instead it stores the email in State.generatedEmailData and injects the email into UserProfile.extractedProfile only when building script request params (including retry cases), and fails fast if the implicit path is hit for ScanStep.

Updates and expands unit tests to cover explicit vs implicit flows, scan-step behavior, pixel emission, and ensuring existing generatedEmailData prevents re-requesting email generation.

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[landomen]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
Learn more

• PIR: Add email fallback #8656
• PIR: Add getEmailData pixel #8642
• PIR: Fix email data handling #8641
• PIR: Clear emailExtractedData on step completion #8612
• PIR: Update completeRequestData to support scans and email extracted data #8583
• PIR: Add email polling mechanism #8581
• PIR: Add handling of GenerateEmail action #8294 👈 (View in Graphite)
• PIR: Add broker step action handler logic #8282
• PIR: Add state engine models for email flexibility #8233
• PIR: Add new email flexibility action models #8232
• develop

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Cursor Bugbot has reviewed your changes and found 2 potential issues.

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[karlenDimla]

We should revisit if we want to fire pixels for scan and optout/email confirmation?

[karlenDimla]

I assume this will still change once we introduce the GetEmailData right?