docs: add standardized comments to all services (Python, Go, Bash)

- Add docs/commenting-standard.md defining per-language comment standards
  (Go godoc, Python PEP-257, C Doxygen, Bash header blocks, SQL banners)

- services/dashboard: 100% docstring coverage (100/100 functions)
  - All FastAPI route handlers, helpers, classes, and models documented
  - Language: French (project convention)

- services/bot-detector: 100% docstring coverage (53/53 symbols)
  - bot_detector.py: 14 functions + module docstring
  - anubis/fetch_rules.py: 9 functions

- shared/python/ja4_common: full docstrings on ClickHouseClient (7 methods)
  and ClickHouseSettings class

- services/correlator: 24 godoc comments added across 6 Go files
  - correlation_service.go: 10 private helpers
  - unixsocket/source.go: 6 parsing/socket helpers
  - correlated_log.go: 4 field extraction helpers
  - orchestrator.go, logger.go, main.go: 4 comments

- services/correlator/scripts/audit-architecture.sh: standardized header block

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

services/dashboard/backend/routes/clustering.py

@@ -222,6 +222,7 @@ def _run_clustering_job(k: int, hours: int, sensitivity: float = 1.0) -> None:
                 continue
 
             def avg_f(key: str, crows: list[dict] = cluster_rows[j]) -> float:
+                """Calcule la moyenne flottante d'un champ numérique sur les lignes du cluster."""
                 return float(np.mean([float(r.get(key) or 0) for r in crows]))
 
             mean_ttl   = avg_f("ttl")
@@ -245,6 +246,7 @@ def _run_clustering_job(k: int, hours: int, sensitivity: float = 1.0) -> None:
             orgs      = [str(r.get("asn_org") or "") for r in cluster_rows[j] if r.get("asn_org")]
 
             def topk(lst: list[str], n: int = 5) -> list[str]:
+                """Retourne les n valeurs les plus fréquentes d'une liste (valeurs vides exclues)."""
                 return [v for v, _ in Counter(lst).most_common(n) if v]
 
             radar = [