test: add empty command name validation test for project config

Adds a test case to verify that empty command names are rejected
in project-level allowed_commands.yaml, matching the behavior already
tested for org-level config. Updates test count to 163.

Addresses review feedback from leonvanzyl.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

test_security.py

@@ -455,6 +455,21 @@ commands:
             print("  FAIL: Non-allowed command 'rustc' should be blocked")
             failed += 1
 
+        # Test 4: Empty command name is rejected
+        config_path.write_text("""version: 1
+commands:
+  - name: ""
+    description: Empty name should be rejected
+""")
+        result = load_project_commands(project_dir)
+        if result is None:
+            print("  PASS: Empty command name rejected in project config")
+            passed += 1
+        else:
+            print("  FAIL: Empty command name should be rejected in project config")
+            print(f"         Got: {result}")
+            failed += 1
+
     return passed, failed