feat: add comic/doodle theme style (#603)

* feat: add comic/doodle theme style with local font

Add a new "comic" theme style that applies hand-drawn aesthetics (Comic Neue
font, bold borders, heavy font weight) while keeping the original light/dark
background colors. Font files are bundled locally to avoid Google Fonts CDN
dependency.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* fix: update DisplaySettings to use renamed theme API and update brand assets

Rename mode/setMode/ThemeMode to brightness/setBrightness/BrightnessMode
to match the refactored useTheme composable. Update favicon and logo.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

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Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>

packages/client/src/components/hermes/files/FileToolbar.vue

@@ -46,7 +46,6 @@ async function handleRefresh() {
 
 .file-toolbar {
   padding: 12px 16px;
-  border-bottom: 1px solid var(--border-color);
 
   @media (max-width: $breakpoint-mobile) {
     padding: 8px 4px;