Improve contact search logic for email matching

[SamuelPlentz]

Enhance contact search to prefer exact email matches before falling back to previous behavior. See #644

[SamuelPlentz]

Description

This PR improves contact selection for the TO tag by preferring an exact email address match.

Problem

browser.contacts.quickSearch() can return multiple contacts when their email addresses are similar.

For example:

• John Doe — doe@example.com
• Jane Doe — jane.doe@example.com

When composing an email to doe@example.com, Thunderbird may return both contacts.

The current implementation simply selects the first contact returned:

let card = cards.find(c => c.type == "contact");

As a result, Quicktext may use Jane Doe's contact information instead of John Doe's, depending on the order of the search results.

Solution

This change first looks for a contact whose PrimaryEmail or SecondEmail exactly matches the recipient address.

If no exact match is found, the existing behavior is retained by falling back to the first contact returned by quickSearch().

let email = states['TO'].data['email'][aIndex].toLowerCase();

// Prefer an exact email address match.
// Thunderbird's quickSearch() may return contacts with similar email addresses, so using the first result can select the wrong contact.
let card = cards.find(c =>
  c.type == "contact" &&
  (
    c.properties.PrimaryEmail?.toLowerCase() == email ||
    c.properties.SecondEmail?.toLowerCase() == email
  )
);

// Fall back to the previous behavior if no exact match is available.
if (!card) {
  card = cards.find(c => c.type == "contact");
}

Testing

Tested with the following contacts:

• John Doe — doe@example.com
• Jane Doe — jane.doe@example.com

When composing an email to doe@example.com, Quicktext now selects John Doe even when Thunderbird returns Jane Doe as the first search result.