chore(aci): migration to fix fallthrough_type on email Actions

[cathteng]

We started handling fallthroughType correctly in dual writing here #106633

But we need a migration to fix the previously migrated email actions

[github-actions]

This PR has a migration; here is the generated SQL for src/sentry/workflow_engine/migrations/0106_fix_email_action_fallthrough_type.py

for 0106_fix_email_action_fallthrough_type in workflow_engine

--
-- Raw Python operation
--
-- THIS OPERATION CANNOT BE WRITTEN AS SQL

[cursor]

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

^{Bugbot Autofix is OFF. To automatically fix reported issues with Cloud Agents, enable Autofix in the Cursor dashboard.}

[cursor]

Translation failure causes misaligned workflow action updates

Medium Severity

When translate_email_action raises ValueError for any rule action, that action is skipped and the loop continues. This causes translated_actions to have fewer items than rule_email_actions, but subsequent translated actions shift to fill the gap. The migration then applies translated_actions[i] to workflow_email_actions[i] by position, causing misalignment. If the 2nd of 3 rule actions fails translation, the 3rd rule action's data gets incorrectly applied to the 2nd workflow action, while the 3rd workflow action is left unmodified.

 

[cursor]

Migration produces schema-violating config for Member/Team actions

Medium Severity

For Member/Team email actions where targetIdentifier is missing or falsy in the Rule, the migration sets config["target_identifier"] = None. However, the EmailActionHandler.config_schema requires target_identifier to be a string (not null) when target_type is USER or TEAM. Since migrations use apps.get_model(), the pre_save schema validation signal is bypassed, allowing invalid data to be saved. When someone later edits the action through normal code paths, schema validation fails with a ValidationError.