Add elapsed run time, per-account results CSV, and a default config path

Summaries now show elapsed wall-clock time since the run started, and every
summary (interim and final) overwrites a results.csv (Object ID, UPN,
persona/status) next to the audit log, so an operator has a plain export
without parsing NDJSON. ConfigPath also now defaults to
./config/persona-engine.json instead of requiring -ConfigPath every run.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

docs/OperationsRunbook.md

@@ -44,7 +44,11 @@ the header line and `PE-SAF-001`.
 A summary appears every `summaryInterval` accounts and once at the end, listing **every** rule
 including disabled and zero-match ones. A rule that never fired and a rule that is not in the
 configuration look identical if zero-match rules are omitted, and that distinction is usually what
-you are looking for.
+you are looking for. Its header shows elapsed wall-clock time since the run started.
+
+Each summary also (re)writes `logging.resultsFileName` (default `results.csv`, next to the audit log)
+with one row per account processed so far — Object ID, UPN, and assigned persona/status — for an
+operator who wants the current population breakdown without parsing NDJSON.
 
 ## Exit codes