diff --git a/paperforge/plugin/src/services/memory-state.ts b/paperforge/plugin/src/services/memory-state.ts
index e3dc0831..9d7197e9 100644
--- a/paperforge/plugin/src/services/memory-state.ts
+++ b/paperforge/plugin/src/services/memory-state.ts
@@ -76,7 +76,8 @@ let _cachedPython: PythonResult | null = null;
 
 // ── Functions ──
 
-export function readPathConfig(vaultPath: string): PathConfig {
+export function readPathConfig(vaultPath: string, _fs?: any): PathConfig {
+  const f = _fs || fs;
   const pfPath = path.join(vaultPath, 'paperforge.json');
   const defaults = {
     system_dir: 'System',
@@ -86,10 +87,10 @@ export function readPathConfig(vaultPath: string): PathConfig {
   };
 
   try {
-    if (!fs.existsSync(pfPath)) {
+    if (!f.existsSync(pfPath)) {
       return { ...defaults, _warning: 'paperforge.json not found; using defaults' };
     }
-    const raw = fs.readFileSync(pfPath, 'utf-8');
+    const raw = f.readFileSync(pfPath, 'utf-8');
     const data = JSON.parse(raw);
     const vc = data.vault_config || {};
     return {
@@ -105,8 +106,8 @@ export function readPathConfig(vaultPath: string): PathConfig {
   }
 }
 
-export function resolveVaultPaths(vaultPath: string): ResolvedPaths {
-  const cfg = readPathConfig(vaultPath);
+export function resolveVaultPaths(vaultPath: string, _fs?: any): ResolvedPaths {
+  const cfg = readPathConfig(vaultPath, _fs);
   const systemDir = path.join(vaultPath, cfg.system_dir, 'PaperForge');
   return {
     vault: vaultPath,
diff --git a/paperforge/plugin/tests/runtime.test.mjs b/paperforge/plugin/tests/runtime.test.ts
similarity index 94%
rename from paperforge/plugin/tests/runtime.test.mjs
rename to paperforge/plugin/tests/runtime.test.ts
index 16fd964b..00b50fc2 100644
--- a/paperforge/plugin/tests/runtime.test.mjs
+++ b/paperforge/plugin/tests/runtime.test.ts
@@ -1,18 +1,14 @@
 /**
- * Vitest tests for runtime.js — resolvePythonExecutable, getPluginVersion, checkRuntimeVersion.
+ * Vitest tests for runtime functions — readPathConfig, resolveVaultPaths,
+ * resolvePythonExecutable, getPluginVersion, checkRuntimeVersion.
  *
  * Uses dependency injection (last parameter) instead of vi.mock to avoid
  * CJS/ESM module mocking limitations in vitest v2.1.x.
  */
 import { describe, it, expect, vi, beforeEach } from 'vitest';
 
-const {
-    readPathConfig,
-    resolveRuntimePaths,
-    resolvePythonExecutable,
-    getPluginVersion,
-    checkRuntimeVersion,
-} = await import('../src/testable.js');
+import { readPathConfig, resolveVaultPaths as resolveRuntimePaths } from "../src/services/memory-state";
+import { resolvePythonExecutable, getPluginVersion, checkRuntimeVersion } from "../src/services/python-bridge";
 
 describe('readPathConfig', () => {
     it('uses vault_config system_dir when present', () => {