test(rate-limits): build Kimi credential-path expectations with path.join

The host-home assertions hardcoded POSIX separators, so they only passed on
a POSIX runner — on a Windows dev machine `join` emits backslashes and all
four cases failed (three assertion mismatches plus a WSL-suite fixture whose
map key never matched the path the fetcher read).

src/main/rate-limits/kimi-fetcher-wsl-home.test.ts

@@ -1,3 +1,4 @@
+import { join } from 'node:path'
 import { beforeEach, describe, expect, it, vi } from 'vitest'
 
 const netFetchMock = vi.hoisted(() => vi.fn())
@@ -20,12 +21,12 @@ vi.mock('node:fs/promises', () => ({
     return contents
   }
 }))
-// Posix-shaped host home so `node:path.join` behaves the same on every test runner.
 vi.mock('node:os', () => ({ homedir: () => '/home/neil' }))
 
 import { fetchKimiRateLimits } from './kimi-fetcher'
 
-const HOST_CREDENTIALS = '/home/neil/.kimi-code/credentials/kimi-code.json'
+// Built with `join` so the key matches the separator the fetcher emits on this runner's platform.
+const HOST_CREDENTIALS = join('/home/neil', '.kimi-code', 'credentials', 'kimi-code.json')
 const WSL_HOME = '\\\\wsl.localhost\\Ubuntu\\home\\neil\\.kimi-code'
 const WSL_CREDENTIALS = `${WSL_HOME}\\credentials\\kimi-code.json`
 

src/main/rate-limits/kimi-fetcher.test.ts

@@ -1,3 +1,4 @@
+import { join } from 'node:path'
 import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
 
 const netFetchMock = vi.hoisted(() => vi.fn())
@@ -55,6 +56,11 @@ const USAGE_RESPONSE = {
   subType: 'TYPE_PURCHASE'
 }
 
+// Built with `join` so the expectation matches the separator the fetcher emits on this platform.
+function hostCredentialsPath(kimiHome: string): string {
+  return join(kimiHome, 'credentials', 'kimi-code.json')
+}
+
 function freshCredentials(): string {
   // expires_at far in the future (seconds).
   return JSON.stringify({ access_token: 'tok-abc', expires_at: 99_999_999_999 })
@@ -161,7 +167,7 @@ describe('fetchKimiRateLimits', () => {
     const result = await fetchKimiRateLimits()
 
     expect(result.status).toBe('ok')
-    expect(fsState.readPaths).toEqual(['/home/test/.kimi-code/credentials/kimi-code.json'])
+    expect(fsState.readPaths).toEqual([hostCredentialsPath('/home/test/.kimi-code')])
   })
 
   it('honors KIMI_CODE_HOME for the host home', async () => {
@@ -172,7 +178,7 @@ describe('fetchKimiRateLimits', () => {
     const result = await fetchKimiRateLimits()
 
     expect(result.status).toBe('ok')
-    expect(fsState.readPaths).toEqual(['/custom/kimi-home/credentials/kimi-code.json'])
+    expect(fsState.readPaths).toEqual([hostCredentialsPath('/custom/kimi-home')])
   })
 
   it('ignores a blank KIMI_CODE_HOME instead of reading from the process cwd', async () => {
@@ -182,6 +188,6 @@ describe('fetchKimiRateLimits', () => {
 
     await fetchKimiRateLimits()
 
-    expect(fsState.readPaths).toEqual(['/home/test/.kimi-code/credentials/kimi-code.json'])
+    expect(fsState.readPaths).toEqual([hostCredentialsPath('/home/test/.kimi-code')])
   })
 })