refactor(coding-agent): extracted bash execution into dedicated executor

- Extracted bash execution logic from bash tool into dedicated BashExecutor with configurable cwd and timeout options.
- Added timeout handling with automatic process termination and timeout-specific result tracking.
- Simplified streaming output handling by replacing rolling buffer with string concatenation.
- Reformatted indentation from spaces to tabs across shell utility files.

packages/coding-agent/src/core/tools/edit.ts

@@ -66,7 +66,12 @@ Usage:
 			// Reject .ipynb files - use NotebookEdit tool instead
 			if (absolutePath.endsWith(".ipynb")) {
 				return {
-					content: [{ type: "text", text: "Cannot edit Jupyter notebooks with the Edit tool. Use the NotebookEdit tool instead." }],
+					content: [
+						{
+							type: "text",
+							text: "Cannot edit Jupyter notebooks with the Edit tool. Use the NotebookEdit tool instead.",
+						},
+					],
 					details: undefined,
 				};
 			}