HIGH: Update the UnreadMessageSummary subject line to emphasize user content

[quinthar]

Strategy:
Our plan to get a billion users involves convincing every business and organization in the world to create a "workspace" for their internal chat. With luck it'll mean that users will be members of many workspaces, groups, and DMs. Additionally, to fight the "tyranny of the straggler", all workspace communications fall back to email.

Problem:
As you use Expensify more for chat, you get more and more email notifications -- and they all contain Expensify Chat in the subject. This feels very spammy: it's like, I get it, it's from Expensify Chat. Consider the following subject lines:

• DM: Expensify Chat between David and Joel
• Group: Expensify Chat between Concierge, David and A Clean
• Room: [Midtown Beer Garden] #announce Expensify Chat
• Thread: [Midtown Beer Garden] Chat Report Expensify Chat

Contrast to Github, which devotes the entire subject line to the user's content:

• [Expensify/react-native-onyx] Fix Prettier diff (PR #442)

Solution:
Streamline the subject line to focus less on us and more on the user's content by:

• Non-Threads: Use the room name (ie, whatever is shown in product in the header) for the subject,

  • DM: David and Joel
  • Group: Concierge, David, and A Clean
  • Room: Midtown Beer Garden / #announce

• Threads: Put the "parent room" in brackets, and the threaded comment after:

  • DM: [David and Joel] What do you think of blah?
  • Group: [Concierge, David, and A Clean] What do you think of blah?
  • Room: [Midtown Beer Garden / #announce] What do you think of blah?
  • Thread in thread: [What do you think of blah?] Bananas, mostly

This preserves "threading" where same-subject messages neatly combine in Gmail. But it prevents the redundant Expensify Chat everywhere. It also has the benefit of reminding the user that DMs, groups, rooms, and threads are all subtly different.

Realtime Slack conversation happening here: https://expensify.slack.com/archives/C066HJM2CAZ/p1703535720130769

[mallenexpensify]

Assigned to me and made daily to try to get more 👀 on this, get an engineer assigned
https://expensify.slack.com/archives/C03SSAQ7P/p1705085261350899

[melvin-bot]

@mallenexpensify Uh oh! This issue is overdue by 2 days. Don't forget to update your issues!

[rlinoz]

Making sure my solution will work here then I will open the remaining PRs

[iwiznia]

Part of this change made it so that I can't filter these emails anymore, can we please do something so that I can?
Some context here staging.new.expensify.com/r/6170818806991248

[mallenexpensify]

Per the link above, @iwiznia 's concern about filters should be alleviated with this

[tgolen]

I've always loved how GH does their email notifications (utilize a no-reply address in the CC field) which also allows them to be filtered based on the action that triggered the notification. I think that would be pretty easy to implement and could work well. Though, we should be careful about spending too much time perfecting these as there could be more valuable work to do elsewhere.

[melvin-bot]

@rlinoz, @mallenexpensify Whoops! This issue is 2 days overdue. Let's get this updated quick!

[rlinoz]

After some discussion we found a good solution and I am implementing it, should put the PRs for review tomorrow.

[melvin-bot]

@rlinoz, @mallenexpensify Uh oh! This issue is overdue by 2 days. Don't forget to update your issues!

[rlinoz]

Auth PR has been merged, Web-E is in review.

[melvin-bot]

@rlinoz, @mallenexpensify Uh oh! This issue is overdue by 2 days. Don't forget to update your issues!

[rlinoz]

Web-E is still in review.

[melvin-bot]

@rlinoz, @mallenexpensify Whoops! This issue is 2 days overdue. Let's get this updated quick!

[rlinoz]

Feature is in staging

[rlinoz]

This is deployed to prod, so closing this one

It created a new bug #37568, which I will get to.