Handle insufficient privileges in pg_stat_statements migration

Wrap CREATE EXTENSION in a PL/pgSQL DO block that catches
insufficient_privilege so the migration completes successfully
even when the DB user is not a superuser.

priv/repo/migrations/20250707214530_enable_pg_stat_statements.exs

@@ -1,7 +1,19 @@
 defmodule Aprsme.Repo.Migrations.EnablePgStatStatements do
   use Ecto.Migration
 
-  def change do
-    execute "CREATE EXTENSION IF NOT EXISTS pg_stat_statements"
+  def up do
+    execute """
+    DO $$
+    BEGIN
+      CREATE EXTENSION IF NOT EXISTS pg_stat_statements;
+    EXCEPTION WHEN insufficient_privilege THEN
+      RAISE NOTICE 'Skipping pg_stat_statements: insufficient privileges (requires superuser)';
+    END;
+    $$
+    """
+  end
+
+  def down do
+    execute "DROP EXTENSION IF EXISTS pg_stat_statements"
   end
 end