Fix series name for themes with a character subdir but no variant

Three layout depths exist under definitions/:
  series/file.json              (e.g. Megumin)
  series/character/file.json    (e.g. Rem, Ram, Beatrice, Miku)
  series/character/variant/file.json  (most themes)

Counting from the end of the path produced wrong series names for the
middle case. Always read the series as the first directory after
'definitions/' instead.

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

src/palette.ts

@@ -47,8 +47,11 @@ export function loadTheme(definitionPath: string, dokiRepoRoot: string): ThemeCo
 
   const variant = hasVariant ? nameParts[nameParts.length - 1] : null;
 
-  // Series directory is 4 levels up when a variant dir exists, 2 levels up otherwise
-  const series = hasVariant ? parts[parts.length - 4] : parts[parts.length - 2];
+  // Series is always the first directory after 'definitions/' regardless of depth.
+  // Counting from the end is fragile because definitions can be 2, 3 or 4 segments
+  // deep (series/file, series/char/file, series/char/variant/file).
+  const defsIdx = parts.lastIndexOf('definitions');
+  const series = parts[defsIdx + 1];
 
   const internalName = ['doki', sanitize(series), sanitize(def.displayName), variant ? sanitize(variant) : null]
     .filter(Boolean)