o prompt: buffer multi-line paste input

Drains additional lines within 50ms of the first line to capture
multi-line pastes in the TUI prompt.

data/scripts/o

@@ -328,6 +328,10 @@ cmd_prompt() {
             printf "\n"
             break
         fi
+        # Drain any remaining lines from a multi-line paste (bracketed paste or fast input)
+        while IFS= read -r -t 0.05 extra_line; do
+            line="$line"$'\n'"$extra_line"
+        done
         if [[ -z "$buf" && "$line" == /* ]]; then
             history -s "$line"
             local cmd="${line#/}"