fix(tui): reopen autocomplete after backspace deletes space

Author: Raviguntakala

packages/opencode/src/cli/cmd/tui/component/prompt/autocomplete.tsx

@@ -457,6 +457,30 @@ export function Autocomplete(props: {
             hide()
             return
           }
+        } else {
+          // Check if autocomplete should reopen (e.g., after backspace deleted a space)
+          const cursorOffset = props.input().cursorOffset
+          if (cursorOffset > 0) {
+            // Check for "/" at position 0 - reopen slash commands
+            if (value.startsWith("/") && !value.slice(0, cursorOffset).match(/\s/)) {
+              show("/")
+              setStore("index", 0)
+              return
+            }
+            // Check for "@" trigger - find the nearest "@" before cursor with no whitespace between
+            const textBeforeCursor = value.slice(0, cursorOffset)
+            const lastAtIndex = textBeforeCursor.lastIndexOf("@")
+            if (lastAtIndex !== -1) {
+              const textBetween = textBeforeCursor.slice(lastAtIndex)
+              const charBeforeAt = lastAtIndex === 0 ? undefined : value[lastAtIndex - 1]
+              const canTrigger = charBeforeAt === undefined || /\s/.test(charBeforeAt)
+              if (canTrigger && !textBetween.match(/\s/)) {
+                show("@")
+                setStore("index", lastAtIndex)
+                return
+              }
+            }
+          }
         }
       },
       onKeyDown(e: KeyEvent) {