opencode: make the themes also accept path

- Removed unnecessary empty-themes test.

tests/modules/programs/opencode/default.nix

@@ -9,5 +9,6 @@
   opencode-agents-path = ./agents-path.nix;
   opencode-commands-path = ./commands-path.nix;
   opencode-mixed-content = ./mixed-content.nix;
-  opencode-themes = ./themes.nix;
+  opencode-themes-inline = ./themes-inline.nix;
+  opencode-themes-path = ./themes-path.nix;
 }

tests/modules/programs/opencode/empty-themes.nix

@@ -1,9 +0,0 @@
-{
-  programs.opencode = {
-    enable = true;
-    themes = { };
-  };
-  nmt.script = ''
-    assertPathNotExists home-files/.config/opencode/themes
-  '';
-}

tests/modules/programs/opencode/themes-path.nix

@@ -0,0 +1,11 @@
+{
+  nmt.script = ''
+    assertFileExists home-files/.config/opencode/themes/my-theme.json
+    assertFileContent home-files/.config/opencode/themes/my-theme.json \
+      ${./my-theme.json}
+  '';
+  programs.opencode = {
+    enable = true;
+    themes.my-theme = ./my-theme.json;
+  };
+}