refactor(core): collapse nested if statements per clippy

Collapsed nested if statements that check related conditions into
single conditions using &&. This improves readability by making
the logical relationship between conditions explicit.

Files changed:
- feedback_extraction.rs: 3 instances of tool_use/final_output checks
- tools/todo.rs: 1 instance of todo completion check

Agent: fowler

crates/g3-core/src/feedback_extraction.rs

@@ -306,8 +306,9 @@ fn try_extract_anthropic_tool_use(response: &str) -> Option<String> {
         if let Some(json_str) = extract_balanced_json(&response[start..]) {
             if let Ok(blocks) = serde_json::from_str::<Vec<Value>>(&json_str) {
                 for block in blocks {
-                    if block.get("type").and_then(|v| v.as_str()) == Some("tool_use") {
+                    if block.get("type").and_then(|v| v.as_str()) == Some("tool_use")
-                        if block.get("name").and_then(|v| v.as_str()) == Some("final_output") {
+                        && block.get("name").and_then(|v| v.as_str()) == Some("final_output")
+                    {
                         if let Some(input) = block.get("input") {
                             if let Some(summary) = input.get("summary").and_then(|v| v.as_str()) {
                                 return Some(summary.to_string());
@@ -318,7 +319,6 @@ fn try_extract_anthropic_tool_use(response: &str) -> Option<String> {
             }
         }
     }
-    }
 
     None
 }
@@ -427,8 +427,9 @@ fn extract_final_output_from_messages(messages: &[Value]) -> Option<String> {
                     }
                 } else if let Some(content_array) = content.as_array() {
                     for block in content_array {
-                        if block.get("type").and_then(|v| v.as_str()) == Some("tool_use") {
+                        if block.get("type").and_then(|v| v.as_str()) == Some("tool_use")
-                            if block.get("name").and_then(|v| v.as_str()) == Some("final_output") {
+                            && block.get("name").and_then(|v| v.as_str()) == Some("final_output")
+                        {
                             if let Some(input) = block.get("input") {
                                 if let Some(summary) = input.get("summary").and_then(|v| v.as_str()) {
                                     return Some(summary.to_string());
@@ -440,7 +441,6 @@ fn extract_final_output_from_messages(messages: &[Value]) -> Option<String> {
             }
         }
     }
-    }
     
     None
 }
@@ -468,14 +468,14 @@ fn is_final_output_tool_call(msg: &Value) -> bool {
         // Check array content (native tool calling)
         if let Some(content_array) = content.as_array() {
             for block in content_array {
-                if block.get("type").and_then(|v| v.as_str()) == Some("tool_use") {
+                if block.get("type").and_then(|v| v.as_str()) == Some("tool_use")
-                    if block.get("name").and_then(|v| v.as_str()) == Some("final_output") {
+                    && block.get("name").and_then(|v| v.as_str()) == Some("final_output")
+                {
                     return true;
                 }
             }
         }
     }
-    }
     
     // Check tool_calls field (OpenAI format)
     if let Some(tool_calls) = msg.get("tool_calls").and_then(|v| v.as_array()) {

crates/g3-core/src/tools/todo.rs

@@ -92,8 +92,8 @@ pub async fn execute_todo_write<W: UiWriter>(
     if !in_planner_mode
         && !has_incomplete
         && (content_str.contains("- [x]") || content_str.contains("- [X]"))
+        && todo_path.exists()
     {
-        if todo_path.exists() {
         match std::fs::remove_file(&todo_path) {
             Ok(_) => {
                 let mut todo = ctx.todo_content.write().await;
@@ -111,7 +111,6 @@ pub async fn execute_todo_write<W: UiWriter>(
             Err(e) => return Ok(format!("❌ Failed to remove todo.g3.md: {}", e)),
         }
     }
-    }
 
     match std::fs::write(&todo_path, content_str) {
         Ok(_) => {