Align at sign trigger condition with hash and slash triggers

- in prompt field, ignore '@' when typed right after another character

├── apps
│   └── editor
│       └── src
│           └── views
│               └── prompt
│                   ├── backend
│                   │   └── message-handlers
│                   │       └── handle-at-sign-quick-pick.ts
│                   └── frontend
│                       └── Main
│                           ├── Main.tsx
│                           └── MainView
│                               └── MainView.tsx
└── packages
    └── ui
        └── src
            └── components
                └── editor
                    └── common
                        └── prompts
                            └── PromptField
                                ├── PromptField.tsx
                                ├── components
                                │   └── Footer
                                │       └── Footer.tsx
                                └── hooks
                                    └── use-handlers
                                        ├── handle-input-change.ts
                                        ├── types.ts
                                        └── use-handlers.ts

Author: robertpiosik

packages/ui/src/components/editor/common/prompts/PromptField/hooks/use-handlers/handle-input-change.ts

@@ -28,15 +28,14 @@ export const create_handle_input_change =
     }
 
     if (char_before_caret == '@') {
-      let should_trigger = true
+      const is_at_start = caret_position == 1
+      let is_after_whitespace = false
       if (caret_position > 1) {
         const char_before_at = new_display_value.charAt(caret_position - 2)
-        if (char_before_at == '@') {
-          should_trigger = false
-        }
+        is_after_whitespace = /\s/.test(char_before_at)
       }
 
-      if (should_trigger) {
+      if (is_at_start || is_after_whitespace) {
         props.on_at_sign_click()
       }
     } else if (char_before_caret == '#') {