test: fix Footer and tokenLimits test failures

- Footer.test.tsx: provide contextWindowSize in mock config to match
  Footer component's new requirement for displaying context usage
- tokenLimits.test.ts: consolidate Kimi K2 tests and update expectations
  to 256K for all variants to match the implementation

packages/cli/src/ui/components/Footer.test.tsx

@@ -23,7 +23,7 @@ const defaultProps = {
 const createMockConfig = (overrides = {}) => ({
   getModel: vi.fn(() => defaultProps.model),
   getDebugMode: vi.fn(() => false),
-  getContentGeneratorConfig: vi.fn(() => ({})),
+  getContentGeneratorConfig: vi.fn(() => ({ contextWindowSize: 131072 })),
   getMcpServers: vi.fn(() => ({})),
   getBlockedMcpServers: vi.fn(() => []),
   ...overrides,