Three test files were mocking the entire '../../shared' barrel, which
corrupted exports for subsequent test files in the same batch run.
Narrow mocks to specific submodules (logger, connected-providers-cache).
Also reverts Bun version pin since the root cause was mock scope, not Bun.
- model-fallback hook: mock selectFallbackProvider and add _resetForTesting()
to test-setup.ts to clear module-level state between files
- fallback-retry-handler: add afterAll(mock.restore) and use mockReturnValueOnce
to prevent connected-providers mock leaking to subsequent test files
- opencode-config-dir: use win32.join for Windows APPDATA path construction
so tests pass on macOS (path.join uses POSIX semantics regardless of
process.platform override)
- system-loaded-version: use resolveSymlink from file-utils instead of
realpathSync to handle macOS /var -> /private/var symlink consistently
All 4456 tests pass (0 failures) on full bun test suite.
YeonGyu-Kim