feat: update the email ui in the template folder

[ngovinh2k2]

What?

Update the email UI in the template folder

Why?

How?

Testing?

• Functional Testing
• Security
• Performance
• Error Handling
• Code Quality
• Documentation
• Database
• Deployment
• Final Review

Anything Else?

[gemini-code-assist]

Code Review

This pull request introduces support for custom email branding, allowing organizations to include their dark/light logos and brand names in emails. It refactors email context rendering, adds filtering by email type to the custom email list view, and updates the organization settings update view to return a fully serialized configuration. The review feedback highlights a duplicate field definition in OrganizationEmailSerializer and points out opportunities to eliminate N+1 query issues in get_theme_logo_url and ListCustomEmailView by utilizing Django's prefetching capabilities.

Important

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[gemini-code-assist]

Using .filter() on the themes related manager triggers a database query every time it is called. When serializing a list of custom emails, this leads to an N+1 query problem (specifically, multiple queries per email item to fetch dark and light themes).

By changing this to use Python's next() with setting.themes.all(), we can leverage Django's prefetch_related cache. Even if prefetching is not used, fetching all themes (typically only 2: light and dark) in a single query is more efficient than executing multiple filtered queries.

Suggested change

	theme = setting.themes.filter(theme_key=theme_key).first()
	theme = next((t for t in setting.themes.all() if t.theme_key == theme_key), None)

[gemini-code-assist]

To completely eliminate the N+1 query problem when listing custom emails, we should optimize the queryset in ListCustomEmailView by pre-fetching the related organization, organization_settings, and themes using select_related and prefetch_related.

Suggested change

	queryset = OrganizationEmail.objects.all()
	organization_field = "organization"
	queryset = OrganizationEmail.objects.select_related(
	"organization__organization_settings"
	).prefetch_related(
	"organization__organization_settings__themes"
	)
	organization_field = "organization"

[gemini-code-assist]

The field "email_type" is duplicated in the fields list of OrganizationEmailSerializer. One of them should be removed to avoid redundancy and keep the code clean.

Suggested change

	"brand_name",
	"email_type",
	"email_type",
	"sender_name",
	"brand_name",
	"email_type",
	"sender_name",