feat: override static_paths and add custom head view for theme injection

asciinema/compose.yaml

@@ -8,7 +8,7 @@ services:
     volumes:
       - asciinema_data:/var/opt/asciinema
       - ./custom.exs:/opt/app/etc/custom.exs:ro
-      - ./theme:/opt/app/priv/static/theme/custom:ro
+      - ./theme:/opt/app/priv/static/theme:ro
     environment:
       SECRET_KEY_BASE: ${ASCIINEMA_SECRET_KEY}
       URL_HOST: ${ASCIINEMA_TRAEFIK_HOST}

asciinema/custom.exs

@@ -16,9 +16,21 @@ config :asciinema, Asciinema.Emails.Mailer,
     versions: [:"tlsv1.2", :"tlsv1.3"]
   ]
 
-# Try to inject custom head HTML (if supported by asciinema)
-config :asciinema, AsciinemaWeb.Endpoint,
-  extra_head_html: """
-  <link rel="stylesheet" href="/theme/custom/custom.css">
-  <link rel="icon" type="image/svg+xml" href="/theme/custom/favicon.svg">
-  """
+# Override static_paths to include our theme directory
+# This allows serving custom CSS and favicon from /theme path
+defmodule AsciinemaWeb do
+  def static_paths, do: ~w(assets fonts images js favicon.ico robots.txt theme)
+end
+
+# Define a custom layout view that injects our theme CSS and favicon
+defmodule AsciinemaWeb.CustomLayoutView do
+  def head(_conn, _assigns) do
+    Phoenix.HTML.raw("""
+    <link rel="stylesheet" href="/theme/custom.css">
+    <link rel="icon" type="image/svg+xml" href="/theme/favicon.svg">
+    """)
+  end
+end
+
+# Override the layout view to use our custom head function
+config :asciinema, AsciinemaWeb.LayoutView, head: &AsciinemaWeb.CustomLayoutView.head/2