Custom Prompt Selection Not Working Correctly

[stars-blue2081]

Description

There are two related UI/functionality issues when working with custom prompts:

1. UI Display Issue:

   • When clicking "Edit Prompt", the recently made Custom Prompt appears
   • However, the default prompts are shown instead of the custom ones
   • Temporary fix: Switching between default and custom prompt fixes the display

2. Prompt Injection Issue:

   • The default Injected Prompt is being used instead of the custom one
   • Default Injected Prompt being sent: "Your current task is [{{task}}]. Balance existing roleplay with completing this task."
   • The custom Injected Prompt is not being used despite being selected from "Edit Prompt"

Expected Behavior

• The selected custom prompt's Injected Prompt should be used instead of the default one

Current Behavior

• When tapping on the "Save Prompt", the button looks like this:
  
• UI shows wrong prompts initially but fixes itself when switching between default/custom
• Task placeholders work correctly
• Default Injected Prompt is being sent instead of the custom one (confirmed via Prompt Inspector and cmd window)

[Cohee1207]

Confirmed, this part was in a rather broken state, I tried my best to make sense of it.

1. Made the prompts actually restore from the metadata on load.
2. The selection of the custom prompt set now persists per-chat.
3. "Save Prompt" renamed to "Update Prompt" to better reflect what it does.
4. Fixed edits to custom prompts not persisting upon page reload.
5. Slightly redesigned the editor popup with more 'logical' layout.