ci: add GitHub Actions workflows with semantic-release auto-versioning

chore: fix all 702 clippy warnings across codebase
- auto-fix 475 via cargo clippy --fix
- fix remaining 227 manually: uninlined_format_args, redundant_closure, match_same_arms,
  underscore_binding, format_push_string, items_after_statements, needless_pass_by_value,
  clone_on_copy, case_sensitive_extension, single_match/let-else, write_with_newline,
  and other clippy lints

src/tool/utility/dir_cache_update.rs

@@ -69,19 +69,19 @@ impl Tool for DirCacheUpdate {
         // Create a one-shot runtime so this tool works from any thread (the
         // agent turn runs on a std::thread that has no tokio context).
         let rt = tokio::runtime::Runtime::new()
-            .map_err(|e| anyhow!("failed to create temp runtime: {}", e))?;
+            .map_err(|e| anyhow!("failed to create temp runtime: {e}"))?;
         rt.block_on(async {
             let cache = dc.write().await;
             cache.set(entries).await;
         });
 
-        Ok(format!("cached {} entries for {}", count, rel))
+        Ok(format!("cached {count} entries for {rel}"))
     }
 }
 
 /// Non-recursively list the immediate entries of `path`.
 ///
-/// Flow: read_dir → flatten Ok entries → collect their paths.
+/// Flow: `read_dir` → flatten Ok entries → collect their paths.
 ///
 /// Why: silently skips unreadable entries (e.g. permission errors)
 /// rather than failing the whole cache update.

src/tool/utility/dir_list.rs

@@ -67,13 +67,13 @@ impl Tool for DirList {
         }
 
         let entries: Vec<String> = fs::read_dir(&path)
-            .map_err(|e| anyhow!("failed to read directory '{}': {}", rel, e))?
-            .filter_map(|e| e.ok())
+            .map_err(|e| anyhow!("failed to read directory '{rel}': {e}"))?
+            .filter_map(std::result::Result::ok)
             .map(|e| {
                 let name = e.file_name().to_string_lossy().to_string();
-                let is_dir = e.file_type().map(|t| t.is_dir()).unwrap_or(false);
+                let is_dir = e.file_type().is_ok_and(|t| t.is_dir());
                 if is_dir {
-                    format!("{}/", name)
+                    format!("{name}/")
                 } else {
                     name
                 }

src/tool/utility/pong.rs

@@ -39,6 +39,6 @@ impl Tool for Pong {
         let msg = args.get("message")
             .and_then(|v| v.as_str())
             .unwrap_or("pong");
-        Ok(format!("pong: {}", msg))
+        Ok(format!("pong: {msg}"))
     }
 }

src/tool/utility/todofinish.rs

@@ -36,9 +36,9 @@ impl Tool for Todofinish {
         }
 
         let content = std::fs::read_to_string(&path)
-            .map_err(|e| anyhow!("failed to read todo.md: {}", e))?;
+            .map_err(|e| anyhow!("failed to read todo.md: {e}"))?;
 
-        let task_index = args.get("task_index").and_then(|v| v.as_i64());
+        let task_index = args.get("task_index").and_then(serde_json::Value::as_i64);
 
         let mut new_content = String::new();
         let mut task_count = 0;
@@ -70,10 +70,10 @@ impl Tool for Todofinish {
         }
 
         std::fs::write(&path, new_content)
-            .map_err(|e| anyhow!("failed to write to todo.md: {}", e))?;
+            .map_err(|e| anyhow!("failed to write to todo.md: {e}"))?;
 
         if let Some(idx) = task_index {
-            Ok(format!("Successfully marked task {} as finished.", idx))
+            Ok(format!("Successfully marked task {idx} as finished."))
         } else {
             Ok("Successfully marked ALL tasks as finished.".to_string())
         }

src/tool/utility/todowrite.rs

@@ -59,17 +59,17 @@ impl Tool for Todowrite {
         let path: PathBuf = ctx.session_dir.join("todo.md");
         let now = chrono::Utc::now();
         let timestamp = now.format("%Y-%m-%d %H:%M:%S");
-        let line = format!("- [ ] {} ({})\n", task, timestamp);
+        let line = format!("- [ ] {task} ({timestamp})\n");
 
         fs::OpenOptions::new()
             .create(true)
             .append(true)
             .open(&path)
-            .map_err(|e| anyhow!("failed to open todo.md: {}", e))?
+            .map_err(|e| anyhow!("failed to open todo.md: {e}"))?
             .write_all(line.as_bytes())
-            .map_err(|e| anyhow!("failed to write to todo.md: {}", e))?;
+            .map_err(|e| anyhow!("failed to write to todo.md: {e}"))?;
 
-        Ok(format!("added task to todo.md: {}", task))
+        Ok(format!("added task to todo.md: {task}"))
     }
 }