feat: implement UI for scheduled messages ⏲️

[Antreesy]

☑️ Resolves

• Fix ⏲️ Scheduled messages / Send later #3954

🖌️ UI Checklist

🖼️ Screenshots / Screencasts

POST

A	B

---

GET

A	B

2025-12-17_15h38_15.mp4

🚧 Tasks

• GET
  • show toggle for views
  • show different toggle for messages due in 24 hours (needs API) 🏗️
  • show any difference that it's not a regular chat?
    • TopBar icon
    • Input should be hidden/disabled, unless user is editing? 🖌️
  • support all MessageItem features
    • replace available message actions
    • replies
    • threads 🖌️
    • thread replies (needs discussion with API) 🏗️
    • silent send 🖌️
    • mentions (needs discussion with API) 🏗️
    • rich content (needs API) 🏗️
    • reference widgets
  • Handle errors
    • Show red toggle
    • Show failed messages (they shouldn't have a sendAt anymore)
• POST
  • show interface for enabling scheduling
  • select time
  • show hint for scheduling
  • support all NewMessage features
    • replies
    • threads
    • thread replies
    • mentions 🖌️
    • silent send
    • rich content (needs API) 🏗️
• PATCH
  • support all NewMessage features
    • plain messages
    • mentions 🖌️
    • only scheduled times
    • thread titles
    • silent send
    • new scheduled time
• DELETE
  • delete scheduled messages
  • clean up store for last deleted
  • clean up with interval / timeout for closest / refetch every time?

🏁 Checklist

• 🌏 Tested with different browsers / clients:
  • Chromium (Chrome / Edge / Opera / Brave)
  • Firefox
  • Safari
  • Talk Desktop
  • Integrations with Files sidebar and other apps
  • Not risky to browser differences / client
• 🖌️ Design was reviewed, approved or inspired by the design team
• ⛑️ Tests are included or not possible
• 📗 User documentation in https://github.com/nextcloud/documentation/tree/master/user_manual/talk has been updated or is not required

[DorraJaouad]

I have not checked the last two commits yet, will come back

[nimishavijay]

Nice, looking great! Overall small changes:

• It seems like the "Message will be sent..." info box is quite far from the input field. Could we move it maybe 1* or 2*(--default-grid-baseline) away from the input field?
• In the 3 dot menu for a scheduled message, delete should always be the last item. Could we move "Send message now" to below "Reschedule" (or even inside the reschedule submenu)
• Wording:
  • "Please choose a date" --> "Choose a time"
  • "Send on custom time" --> "Send at custom time" (I think)
  • "Send message now" --> "Send now"
  • "Edit message" --> "Edit" (even in the normal message action menu)
• Icons:
  • use the outlined version of the send and send later icons

Similar to the initial version of threads I suspect it is difficult to see clearly when we have switch to the scheduled messages view, so some changes to improve that:

• Remove the start call, meetings, etc buttons from the convo header inside
• can we change the conversation title to Scheduled messages and subline in [convo name] (if it is a direct message to [person name])
• Nice-to-have: in the list of scheduled messages could we add "Send on" in the date separators, so Send on December 18th

From issue:

• if there are scheduled messages, the button is shown next to the input field. It disappears when the input field is focused
• If there are no scheduled messages and user is scheduling one, once they click send (or press enter) the clock icon button will appear as confirmation that the message is scheduled.
• nice-to-have: the appearance of this button is animated (input field shrinks and button appears)
• If there are scheduled messages and user is scheduling one, once they click send, the existing clock icon button should have a little animation to confirm that the message was scheduled, something like this:

[DorraJaouad]

GTG

[nimishavijay]

Looking great! :)