o prompt: use . as send trigger, empty lines add newlines

data/scripts/o

@@ -252,7 +252,7 @@ cmd_prompt() {
     path="session/$s/agent/$a"
     
     echo "[$s/$a]"
-    echo "Enter prompts (blank line sends, Ctrl+D exits)."
+    echo "Type . on a blank line to send, Ctrl+D to exit."
     echo "Slash commands: /stop /compact /kill /clear /model /backend /cwd /help"
     echo ""
 
@@ -298,10 +298,18 @@ cmd_prompt() {
             esac
             continue
         fi
+        if [[ "$line" == "." ]]; then
+            # Send prompt on "." alone
+            if [[ -n "$buf" ]]; then
+                history -s "$buf"
+                printf '%s\n' "$buf" | ollie-9p write "$path/prompt"
+                buf=""
+            fi
+            continue
+        fi
         if [[ -z "$line" && -n "$buf" ]]; then
-            history -s "$buf"
-            printf '%s\n' "$buf" | ollie-9p write "$path/prompt"
-            buf=""
+            # Empty line during multi-line input: append newline
+            buf="$buf"$'\n'
         elif [[ -z "$line" ]]; then
             continue
         else