consolidate image serving and clean up pipeline

Move all image URL logic into ProductImage.url/2 and thumbnail_url/1,
remove dead on-demand generation code from Optimizer, strip controller
routes down to SVG recolor only, fix mockup startup check to verify all
variant formats, and isolate test image cache directory.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

test/simpleshop_theme_web/controllers/image_controller_test.exs

@@ -3,81 +3,9 @@ defmodule SimpleshopThemeWeb.ImageControllerTest do
 
   alias SimpleshopTheme.Media
 
-  # Minimal valid PNG (1x1 transparent pixel)
-  @png_binary <<137, 80, 78, 71, 13, 10, 26, 10>>
   @svg_content ~s(<svg xmlns="http://www.w3.org/2000/svg"><circle fill="#000000" r="10"/></svg>)
   @sample_jpeg File.read!("test/fixtures/sample_1200x800.jpg")
 
-  describe "show/2" do
-    test "returns 404 for non-existent image", %{conn: conn} do
-      conn = get(conn, ~p"/images/#{Ecto.UUID.generate()}")
-      assert response(conn, 404) =~ "Image not found"
-    end
-
-    test "serves image with proper content type and caching headers", %{conn: conn} do
-      # Upload a real JPEG which gets converted to WebP
-      {:ok, image} =
-        Media.upload_image(%{
-          image_type: "logo",
-          filename: "test.jpg",
-          content_type: "image/jpeg",
-          file_size: byte_size(@sample_jpeg),
-          data: @sample_jpeg
-        })
-
-      conn = get(conn, ~p"/images/#{image.id}")
-
-      assert response(conn, 200)
-      # Image is converted to WebP for storage
-      assert get_resp_header(conn, "content-type") == ["image/webp; charset=utf-8"]
-      assert get_resp_header(conn, "cache-control") == ["public, max-age=31536000, immutable"]
-      assert get_resp_header(conn, "etag") == [~s("#{image.id}")]
-    end
-  end
-
-  describe "thumbnail/2" do
-    test "returns 404 for non-existent image", %{conn: conn} do
-      conn = get(conn, ~p"/images/#{Ecto.UUID.generate()}/thumbnail")
-      assert response(conn, 404) =~ "Image not found"
-    end
-
-    test "generates thumbnail on-demand and serves as JPEG", %{conn: conn} do
-      # Upload a real image to test thumbnail generation
-      {:ok, image} =
-        Media.upload_image(%{
-          image_type: "logo",
-          filename: "test.jpg",
-          content_type: "image/jpeg",
-          file_size: byte_size(@sample_jpeg),
-          data: @sample_jpeg
-        })
-
-      conn = get(conn, ~p"/images/#{image.id}/thumbnail")
-
-      assert response(conn, 200)
-      # Thumbnail is served as JPEG
-      assert get_resp_header(conn, "content-type") == ["image/jpeg; charset=utf-8"]
-      assert get_resp_header(conn, "cache-control") == ["public, max-age=31536000, immutable"]
-    end
-
-    test "falls back to full image when image data is invalid", %{conn: conn} do
-      # This uses an invalid PNG header that can't be processed
-      {:ok, image} =
-        Media.upload_image(%{
-          image_type: "logo",
-          filename: "test.png",
-          content_type: "image/png",
-          file_size: byte_size(@png_binary),
-          data: @png_binary
-        })
-
-      conn = get(conn, ~p"/images/#{image.id}/thumbnail")
-
-      # Falls back to WebP since that's what we tried to convert to
-      assert response(conn, 200)
-    end
-  end
-
   describe "recolored_svg/2" do
     test "returns 404 for non-existent image", %{conn: conn} do
       conn = get(conn, ~p"/images/#{Ecto.UUID.generate()}/recolored/ff6600")
@@ -88,10 +16,10 @@ defmodule SimpleshopThemeWeb.ImageControllerTest do
       {:ok, image} =
         Media.upload_image(%{
           image_type: "logo",
-          filename: "test.png",
-          content_type: "image/png",
-          file_size: byte_size(@png_binary),
-          data: @png_binary
+          filename: "test.jpg",
+          content_type: "image/jpeg",
+          file_size: byte_size(@sample_jpeg),
+          data: @sample_jpeg
         })
 
       conn = get(conn, ~p"/images/#{image.id}/recolored/ff6600")