fix(dream): allow LLM to retry on tool errors instead of failing immediately

Dream Phase 2 uses fail_on_tool_error=True, which terminates the entire
run on the first tool error (e.g. old_text not found in edit_file).
Normal agent runs default to False so the LLM can self-correct and retry.
Dream should behave the same way.

nanobot/agent/memory.py

@@ -627,7 +627,7 @@ class Dream:
                 model=self.model,
                 max_iterations=self.max_iterations,
                 max_tool_result_chars=self.max_tool_result_chars,
-                fail_on_tool_error=True,
+                fail_on_tool_error=False,
             ))
             logger.debug(
                 "Dream Phase 2 complete: stop_reason={}, tool_events={}",