fix(sentinel): deduplicate configured plugins and polish IT release note

docs/it/about/index.md

@@ -52,7 +52,7 @@ Sviluppato da [PythonWoods](https://github.com/PythonWoods), è progettato per e
     ---
 
     Storico completo delle release e policy della linea attiva.
-    La linea 0.4.x e stata abbandonata; la stabilizzazione attiva e 0.5.x.
+    La linea 0.4.x è stata abbandonata; la stabilizzazione attiva è la 0.5.x.
 
     [:lucide-arrow-right: Leggi](https://github.com/PythonWoods/zenzic/blob/main/CHANGELOG.md)
 

src/zenzic/core/rules.py

@@ -774,7 +774,13 @@ def load_selected_rules(self, plugin_ids: Sequence[str]) -> list[BaseRule]:
         """
         from zenzic.core.exceptions import PluginContractError  # deferred: avoid circular import
 
-        requested = [pid.strip() for pid in plugin_ids if pid.strip()]
+        requested: list[str] = []
+        seen: set[str] = set()
+        for pid in plugin_ids:
+            cleaned = pid.strip()
+            if cleaned and cleaned not in seen:
+                seen.add(cleaned)
+                requested.append(cleaned)
         if not requested:
             return []
 

tests/test_rules.py

@@ -15,6 +15,7 @@
     AdaptiveRuleEngine,
     BaseRule,
     CustomRule,
+    PluginRegistry,
     RuleFinding,
     Violation,
     VSMBrokenLinkRule,
@@ -264,6 +265,34 @@ def test_scan_docs_with_unknown_plugin_raises_contract_error(tmp_path: Path) ->
         scan_docs_references(tmp_path, config)
 
 
+def test_plugin_registry_deduplicates_requested_plugin_ids(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """Duplicate plugin IDs are loaded once while preserving declaration order."""
+
+    class _EP:
+        def __init__(self, name: str) -> None:
+            self.name = name
+
+    registry = PluginRegistry()
+    monkeypatch.setattr(
+        registry,
+        "_entry_points",
+        lambda: [_EP("acme"), _EP("beta")],
+    )
+
+    loaded_names: list[str] = []
+
+    def _fake_load(ep: _EP) -> BaseRule:
+        loaded_names.append(ep.name)
+        return _PluginTodoRule()
+
+    monkeypatch.setattr(registry, "_load_entry_point", _fake_load)
+
+    _rules = registry.load_selected_rules(["acme", "acme", "beta", "acme"])  # noqa: F841
+    assert loaded_names == ["acme", "beta"]
+
+
 # ─── Cross-adapter custom rules (Dev 4 mandate) ───────────────────────────────