fix(default-mode): skip ultrawork system prompt when ralph_loop is also enabled

When both default_mode.ultrawork and default_mode.ralph_loop are true,
the ralph loop handles ultrawork behavior via its continuation mechanism
(prepends 'ultrawork' to each iteration prompt). Injecting the ultrawork
system prompt on top would be redundant — the continuation prompt
re-triggers keyword detection, which defeats the purpose of invisible
system prompt injection.

The ultrawork flag still controls loop behavior (500 max iterations +
Oracle verification gate) via chat-message.ts startLoop({ ultrawork }).

src/plugin/system-transform.ts

@@ -12,6 +12,13 @@ export function createSystemTransformHandler(
   return async (input, output): Promise<void> => {
     if (!defaultMode?.ultrawork || !getUltraworkMessage) return
 
+    // When ralph_loop is also enabled, skip system prompt injection: the loop's
+    // own continuation mechanism handles ultrawork re-injection on each iteration.
+    // Injecting both would be redundant — the continuation prompt prepends
+    // "ultrawork" and re-triggers keyword detection, defeating invisibility.
+    // The `ultrawork` flag still controls loop behavior (500 iters + Oracle gate).
+    if (defaultMode?.ralph_loop) return
+
     // Avoid re-injecting if the ultrawork prompt is already in the system prompt
     // (e.g. after compaction the system prompt is rebuilt and this hook fires again)
     if (output.system.some((part) => part.includes(ULTRAWORK_MODE_TAG))) return