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/show-can-create-agent-does-not-block-code-create.good.al

@@ -0,0 +1,25 @@
+codeunit 50100 "Sales Review Agent Factory"
+{
+    procedure ShowCanCreateAgent(): Boolean
+    var
+        AgentSystemPermissions: Codeunit "Agent System Permissions";
+    begin
+        // Hides the type from non-admins in the UI. Does not block Agent.Create.
+        exit(AgentSystemPermissions.CurrentUserHasCanManageAllAgentsPermission());
+    end;
+
+    procedure CreateIfAllowed()
+    var
+        Agent: Codeunit Agent;
+        AgentSystemPermissions: Codeunit "Agent System Permissions";
+        TempAgentAccessControl: Record "Agent Access Control" temporary;
+    begin
+        if not AgentSystemPermissions.CurrentUserHasCanManageAllAgentsPermission() then
+            Error('Only agent administrators can create this agent.');
+        Agent.Create(
+            Enum::"Agent Metadata Provider"::"Sales Review Agent",
+            'SALESREVIEW',
+            'Sales Review Agent',
+            TempAgentAccessControl);
+    end;
+}