fix: tighten project instruction path handling

packages/util/paths/src/index.ts

@@ -0,0 +1,26 @@
+/**
+ * Shared filesystem path helpers for DeepSeek Harness user data.
+ *
+ * @module @deepseek-ai/dsh-paths
+ */
+
+import { homedir } from 'node:os'
+import { join } from 'node:path'
+
+/** Directory name for the default DeepSeek Harness home under the OS home. */
+export const DSH_HOME_DIR_NAME = '.dsh'
+
+/** Stable user-facing display form for the default DeepSeek Harness home. */
+export const DEFAULT_DSH_HOME_DISPLAY = `~/${DSH_HOME_DIR_NAME}`
+
+/** Resolve the default DeepSeek Harness home using Node's platform path rules. */
+export function defaultDshHome(): string {
+  return join(homedir(), DSH_HOME_DIR_NAME)
+}
+
+/** Expand `~`, `~/...`, and Windows-style `~\...` prefixes against the OS home. */
+export function expandHomePath(path: string): string {
+  if (path === '~') return homedir()
+  if (path.startsWith('~/') || path.startsWith('~\\')) return join(homedir(), path.slice(2))
+  return path
+}