Retain infrastructure names and share/mount roots behind policy switches

Add a `retain` block to privacy_policy.json (all on by default) so assessments
show software, services, processes, tasks, shares/mounts and private peer IPs.
Values pass an identifier-pattern filter (digit runs, SSN/phone, e-mail, charset,
length, path depth). Accounts, command lines, child paths, filenames and public
peer IPs stay omitted. Linux collector and Windows PowerShell collectors updated;
tests cover retention, withholding and all-switches-off.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

tests/test_scoring.py

@@ -198,7 +198,7 @@ class ScoringRegressionTests(unittest.TestCase):
             export_json(output,data,assess(data))
             clean=load_inventory(output)
             self.assertEqual(len(clean['inventory']['services']),86)
-            self.assertNotEqual(clean['server']['hostname'], data['server']['hostname'])
+            self.assertEqual(clean['server']['hostname'], data['server']['hostname'])  # infrastructure hostname retained by default policy
 
     def test_custom_jobs_not_misclassified_by_substrings_and_zero_points_maintenance(self):
         data=fixture('clean_windows')