feat(coding-agent): refactored eval tool to single-step execution

- Transitioned the eval tool from batch multi-cell execution to a single-step input structure with flat parameters.
- Updated core agent logic, UI components, and documentation to support state persistence across incremental eval calls.
- Restricted bash tool capabilities by requiring explicit use of `read` or `find` instead of `ls` or `find`.
- Added support for Ruby and Julia language runtimes to the eval tool and associated web renderers.

packages/coding-agent/test/agent-session-python-cleanup.test.ts

@@ -426,7 +426,7 @@ describe("AgentSession python cleanup", () => {
 		expect(EvalTool).toBeDefined();
 		let toolExecutionSettled = false;
 		const toolExecution = EvalTool!
-			.execute("call-id", { cells: [{ language: "py", code: "print('tool')" }] }, undefined, undefined, undefined)
+			.execute("call-id", { language: "py", code: "print('tool')" }, undefined, undefined, undefined)
 			.finally(() => {
 				toolExecutionSettled = true;
 			});
@@ -652,13 +652,7 @@ describe("AgentSession python cleanup", () => {
 		expect(EvalTool).toBeDefined();
 		const disposeSession = session.dispose();
 		await expect(
-			EvalTool!.execute(
-				"call-id",
-				{ cells: [{ language: "py", code: "print('late')" }] },
-				undefined,
-				undefined,
-				undefined,
-			),
+			EvalTool!.execute("call-id", { language: "py", code: "print('late')" }, undefined, undefined, undefined),
 		).rejects.toThrow("Python execution is unavailable while session disposal is in progress");
 		await disposeSession;
 		expect(executeSpy).not.toHaveBeenCalled();
@@ -693,7 +687,7 @@ describe("AgentSession python cleanup", () => {
 		expect(EvalTool).toBeDefined();
 		const execution = EvalTool!.execute(
 			"call-id",
-			{ cells: [{ language: "py", code: "print('late after artifact')" }] },
+			{ language: "py", code: "print('late after artifact')" },
 			undefined,
 			undefined,
 			undefined,