fix(cli): use fileURLToPath for cross-platform cwd path compatibility

The issue was that new URL().pathname returns Unix-style paths on Windows
(e.g., /D:/a/skillhub/...) which Bun.spawn() cannot resolve correctly.
Using fileURLToPath() converts the URL to a proper platform-specific path.

Changes:
- cli/test/helpers/run-cli.ts: use fileURLToPath for cwd
- cli/test/integration/version-command.test.ts: same fix for build spawn

cli/test/helpers/run-cli.ts

@@ -1,4 +1,5 @@
 import { existsSync } from 'node:fs'
+import { fileURLToPath } from 'node:url'
 
 export async function runCli(args: string[], env: Record<string, string> = {}) {
   // Use Bun.which() to find bun in PATH, but verify it exists
@@ -7,7 +8,7 @@ export async function runCli(args: string[], env: Record<string, string> = {}) {
 
   const proc = Bun.spawn({
     cmd: [bunPath, 'src/index.ts', ...args],
-    cwd: new URL('../../', import.meta.url).pathname,
+    cwd: fileURLToPath(new URL('../../', import.meta.url)),
     env: { ...process.env, ...env },
     stdout: 'pipe',
     stderr: 'pipe'

cli/test/integration/version-command.test.ts

@@ -2,6 +2,7 @@ import { describe, expect, test } from 'bun:test'
 import { mkdtemp, writeFile } from 'node:fs/promises'
 import { tmpdir } from 'node:os'
 import { join } from 'node:path'
+import { fileURLToPath } from 'node:url'
 import { runCli } from '../helpers/run-cli'
 
 describe('version command', () => {
@@ -31,7 +32,7 @@ describe('version command', () => {
     const bunPath = process.execPath
     const build = Bun.spawn({
       cmd: [bunPath, 'build', 'src/index.ts', '--target=node', `--outfile=${outfile}`],
-      cwd: new URL('../../', import.meta.url).pathname,
+      cwd: fileURLToPath(new URL('../../', import.meta.url)),
       stdout: 'pipe',
       stderr: 'pipe'
     })