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.bad.al

@@ -0,0 +1,36 @@
+codeunit 50100 "Sales Review Agent Factory"
+{
+    procedure ShowCanCreateAgent(): Boolean
+    begin
+        // Author intends this to forbid all creates. It only hides the UI tile.
+        exit(false);
+    end;
+}
+
+pageextension 50100 "Sales Order List Agent Create" extends "Sales Order List"
+{
+    actions
+    {
+        addlast(Processing)
+        {
+            action(CreateAgent)
+            {
+                ApplicationArea = All;
+                Caption = 'Create review agent';
+
+                trigger OnAction()
+                var
+                    Agent: Codeunit Agent;
+                    TempAgentAccessControl: Record "Agent Access Control" temporary;
+                begin
+                    // Still succeeds for any caller with permission to run this action.
+                    Agent.Create(
+                        Enum::"Agent Metadata Provider"::"Sales Review Agent",
+                        'SALESREVIEW',
+                        'Sales Review Agent',
+                        TempAgentAccessControl);
+                end;
+            }
+        }
+    }
+}