pathogens: Report compatible workflows as separate setup checks

Helpful to ensure that their directories exist as expected to catch
registration vs. reality mismatches.

Author: tsibley

nextstrain/cli/pathogens.py

@@ -496,10 +496,10 @@ def test_compatibility() -> SetupTestResult:
             if not self.registered_workflows():
                 return msg + "\n(no workflows registered)", False
 
-            if not (compatible_workflows := self.compatible_workflows("nextstrain run")):
+            if not self.compatible_workflows("nextstrain run"):
                 return msg + "\n(no workflows registered as compatible)", False
 
-            return msg + f"\nCompatible workflows: {list(compatible_workflows.keys())}", True
+            return msg, True
 
         return [
             ('downloaded',
@@ -509,6 +509,9 @@ def test_compatibility() -> SetupTestResult:
                 self.registration_path.is_file()),
 
             test_compatibility(),
+
+            *((f'`nextstrain run` workflow {name!r} exists', self.workflow_path(name).is_dir())
+                for name in self.compatible_workflows("nextstrain run")),
         ]