style(deps): migrated from Prettier to Biome and updated formatting rules

- Removed Prettier configuration files (.prettierignore and .prettierrc) and migrated formatting to Biome.
- Updated Biome configuration from version 2.3.11 to 2.3.12 and changed arrowParentheses rule from 'always' to 'asNeeded'.
- Pinned @biomejs/biome dependency to exact version 2.3.12 in package.json and bun.lock.
- Applied consistent arrow function formatting across 489 files by removing unnecessary parentheses around single parameters.
- Removed blank lines after comment blocks and reorganized imports for consistency across the codebase.

packages/coding-agent/test/tools/python-execution.test.ts

@@ -60,7 +60,7 @@ describe("python tool execution", () => {
 				reset: true,
 			}),
 		);
-		const text = result.content.find((item) => item.type === "text")?.text;
+		const text = result.content.find(item => item.type === "text")?.text;
 		expect(text).toBe("ok");
 
 		executeSpy.mockRestore();