fix(rendering): replace raising read_template_file with try_read in macro templates (CSM-028)

test/bds/csm028_broad_rescue_test.exs

@@ -0,0 +1,22 @@
+defmodule BDS.CSM028BroadRescueTest do
+  use ExUnit.Case, async: true
+
+  describe "source-level: no broad rescue in render_macro_template" do
+    test "filters.ex has no rescue _error or rescue _ clauses" do
+      source = File.read!("lib/bds/rendering/filters.ex")
+      refute source =~ ~r/rescue\s+_\w*\s*->/, "Found broad rescue clause in filters.ex"
+    end
+
+    test "filters.ex does not call read_template_file (which raises)" do
+      source = File.read!("lib/bds/rendering/filters.ex")
+
+      refute source =~ "read_template_file",
+             "render_macro_template should use try_read, not read_template_file"
+    end
+
+    test "filters.ex uses FileSystem.try_read for macro templates" do
+      source = File.read!("lib/bds/rendering/filters.ex")
+      assert source =~ "FileSystem.try_read"
+    end
+  end
+end