all: support hiding subconvo output

Some of it is systematically noisy.
diff --git a/claudetool/codereview/llm_review.go b/claudetool/codereview/llm_review.go
index 15205e7..32a8e00 100644
--- a/claudetool/codereview/llm_review.go
+++ b/claudetool/codereview/llm_review.go
@@ -32,6 +32,7 @@
 	info := conversation.ToolCallInfoFromContext(ctx)
 	convo := info.Convo.SubConvo()
 	convo.PromptCaching = false
+	convo.Hidden = true
 	convo.SystemPrompt = strings.TrimSpace(llmCodereviewPrompt)
 	initialMessage := llm.UserStringMessage("<diff>\n" + string(out) + "\n</diff>")
 
diff --git a/claudetool/pre-commit.go b/claudetool/pre-commit.go
index 306c7b9..f8fe5a0 100644
--- a/claudetool/pre-commit.go
+++ b/claudetool/pre-commit.go
@@ -55,6 +55,7 @@
 
 	info := conversation.ToolCallInfoFromContext(ctx)
 	sub := info.Convo.SubConvo()
+	sub.Hidden = true
 	sub.PromptCaching = false
 
 	sub.SystemPrompt = `Analyze the provided git commit messages to identify consistent patterns, including but not limited to: