feat(community/agents): add AL agent quality guidance

- add 20 agent knowledge rules with good and bad AL samples
- clarify setup dialog shape, temporary persistence, permissions, profiles, instructions, capability registration, and interface wiring
- add the community-owned AL agents review skill
- make review fixture discovery layer-aware with custom, community, and Microsoft precedence
- document layer-aware evaluation behavior

community/knowledge/agents/bind-agent-subscribers-only-in-agent-session.good.al

@@ -0,0 +1,21 @@
+codeunit 50102 "Agent Session Events"
+{
+    Access = Internal;
+    SingleInstance = true;
+    InherentEntitlements = X;
+    InherentPermissions = X;
+
+    var
+        GlobalAgentEvents: Codeunit "Sales Review Agent Events";
+
+    [EventSubscriber(ObjectType::Codeunit, Codeunit::"System Initialization", OnAfterInitialization, '', false, false)]
+    local procedure RegisterSubscribersOnAfterInitialization()
+    var
+        AgentSession: Codeunit "Agent Session";
+        AgentMetadataProvider: Enum "Agent Metadata Provider";
+    begin
+        if not AgentSession.IsAgentSession(AgentMetadataProvider) then
+            exit;
+        if BindSubscription(GlobalAgentEvents) then;
+    end;
+}