Fix p's weird corrupt theme data crashing theme engine

For whatever reasons fse's p's theme data didn't have color information for some theme shadow, which crashed the whole thing. Probably caused by some pre-1.0 theme editor idk.

https://shigusegubu.club/notice/A3V392Cl2T6W9FApyi

src/services/style_setter/style_setter.js

@@ -242,9 +242,18 @@ export const generateShadows = (input, colors) => {
     panelHeader: 'panel',
     input: 'input'
   }
-  const inputShadows = input.shadows && !input.themeEngineVersion
-    ? shadows2to3(input.shadows, input.opacity)
-    : input.shadows || {}
+
+  const cleanInputShadows = Object.fromEntries(
+    Object.entries(input.shadows)
+      .map(([name, shadowSlot]) => [
+        name,
+        // defaulting color to black to avoid potential problems
+        shadowSlot.map(shadowDef => ({ color: '#000000', ...shadowDef }))
+      ])
+  )
+  const inputShadows = cleanInputShadows && !input.themeEngineVersion
+    ? shadows2to3(cleanInputShadows, input.opacity)
+    : cleanInputShadows || {}
   const shadows = Object.entries({
     ...DEFAULT_SHADOWS,
     ...inputShadows