refactor(coding-agent): reorganized test files to proper test directory structure

- Moved test files from src/core to test/core directory.
- Moved test files from src/core/tools to test/tools directory.
- Moved test files from src/discovery to test/discovery directory.
- Updated import paths to reflect new test file locations.

packages/coding-agent/test/core/python-kernel-session.test.ts

@@ -0,0 +1,87 @@
+import { afterEach, beforeEach, describe, expect, it } from "bun:test";
+import { disposeAllKernelSessions, executePython } from "../../src/core/python-executor";
+import type { KernelExecuteOptions, KernelExecuteResult } from "../../src/core/python-kernel";
+import { PythonKernel } from "../../src/core/python-kernel";
+
+class FakeKernel {
+	executeCalls = 0;
+	shutdownCalls = 0;
+	alive = true;
+	readonly id: string;
+
+	constructor(id: string) {
+		this.id = id;
+	}
+
+	async execute(_code: string, options?: KernelExecuteOptions): Promise<KernelExecuteResult> {
+		this.executeCalls += 1;
+		options?.onChunk?.("ok\n");
+		return { status: "ok", cancelled: false, timedOut: false, stdinRequested: false };
+	}
+
+	async shutdown(): Promise<void> {
+		this.shutdownCalls += 1;
+		this.alive = false;
+	}
+
+	isAlive(): boolean {
+		return this.alive;
+	}
+
+	async ping(): Promise<boolean> {
+		return this.alive;
+	}
+}
+
+describe("executePython kernel reuse", () => {
+	const originalStart = PythonKernel.start;
+	let startCalls = 0;
+	let kernels: FakeKernel[] = [];
+
+	beforeEach(() => {
+		process.env.OMP_PYTHON_SKIP_CHECK = "1";
+		startCalls = 0;
+		kernels = [];
+		PythonKernel.start = (async () => {
+			startCalls += 1;
+			const kernel = new FakeKernel(`kernel-${startCalls}`);
+			kernels.push(kernel);
+			return kernel as unknown as PythonKernel;
+		}) as typeof PythonKernel.start;
+	});
+
+	afterEach(async () => {
+		PythonKernel.start = originalStart;
+		await disposeAllKernelSessions();
+	});
+
+	it("reuses kernels for session mode", async () => {
+		await executePython("print('one')", { cwd: "/tmp", sessionId: "session-a", kernelMode: "session" });
+		await executePython("print('two')", { cwd: "/tmp", sessionId: "session-a", kernelMode: "session" });
+
+		expect(startCalls).toBe(1);
+		expect(kernels[0]?.executeCalls).toBe(2);
+	});
+
+	it("creates and disposes per-call kernels", async () => {
+		await executePython("print('one')", { cwd: "/tmp", kernelMode: "per-call" });
+		await executePython("print('two')", { cwd: "/tmp", kernelMode: "per-call" });
+
+		expect(startCalls).toBe(2);
+		expect(kernels[0]?.shutdownCalls).toBe(1);
+		expect(kernels[1]?.shutdownCalls).toBe(1);
+	});
+
+	it("resets the session kernel when requested", async () => {
+		await executePython("print('one')", { cwd: "/tmp", sessionId: "session-b", kernelMode: "session" });
+		await executePython("print('two')", {
+			cwd: "/tmp",
+			sessionId: "session-b",
+			kernelMode: "session",
+			reset: true,
+		});
+
+		expect(startCalls).toBe(2);
+		expect(kernels[0]?.shutdownCalls).toBe(1);
+	});
+});