fix(test): ensure lock cleanup before manual mkdir in tests

Add explicit cleanup before manually creating lock directories in tests.
This prevents EEXIST errors when tests don't fully clean up or run in
quick succession.

Author: jdalton

test/process-lock.test.ts

@@ -71,6 +71,11 @@ describe('process-lock', () => {
     })
 
     it('should remove stale lock and acquire', async () => {
+      // Ensure lock doesn't exist before we manually create it.
+      if (existsSync(lockPath)) {
+        await safeDelete(lockPath, { force: true })
+      }
+
       // Create a lock directory manually.
       mkdirSync(lockPath)
 
@@ -88,6 +93,11 @@ describe('process-lock', () => {
     })
 
     it('should retry with exponential backoff', async () => {
+      // Ensure lock doesn't exist before we manually create it.
+      if (existsSync(lockPath)) {
+        await safeDelete(lockPath, { force: true })
+      }
+
       // Create lock manually to simulate another process holding it.
       mkdirSync(lockPath)
 
@@ -112,6 +122,11 @@ describe('process-lock', () => {
     })
 
     it('should respect custom stale timeout', async () => {
+      // Ensure lock doesn't exist before we manually create it.
+      if (existsSync(lockPath)) {
+        await safeDelete(lockPath, { force: true })
+      }
+
       // Create a lock that's 6 seconds old.
       mkdirSync(lockPath)
       const sixSecondsAgo = Date.now() - 6_000