fix(dashboard): honor sidebar theme preference on all routes (#738)

* fix(dashboard): honor sidebar theme preference on all routes

Stop forcing light mode on public org-site pages. Use one ModeWatcher
everywhere so light/dark/system follows the sidebar footer toggle.

- Remove isPublicOrgSitePage forced-light routing (#716 behavior)
- Fix theme toggle active state (light/dark/system mutually exclusive)

Co-authored-by: Rotimi Best <rotimi-best@users.noreply.github.com>

* fix(dashboard): apply sidebar color mode instead of browser default

ModeWatcher defaulted to system, so prefers-color-scheme won unless
localStorage happened to match. AppModeWatcher now:

- Defaults new visitors to light (not system)
- Injects FOUC script with the same default
- Only tracks OS appearance when the user picks System in the sidebar
- Re-syncs explicit light/dark from mode-watcher localStorage on load

Co-authored-by: Rotimi Best <rotimi-best@users.noreply.github.com>

---------

Co-authored-by: Cursor Agent <cursoragent@cursor.com>
Co-authored-by: Rotimi Best <rotimi-best@users.noreply.github.com>

apps/dashboard/src/lib/features/app/app-mode-watcher.svelte

@@ -0,0 +1,37 @@
+<script lang="ts">
+  import { browser } from '$app/environment';
+  import {
+    ModeWatcher,
+    createInitialModeExpression,
+    setMode,
+    systemPrefersMode,
+    userPrefersMode
+  } from '@cio/ui/base/dark-mode';
+
+  import { MODE_STORAGE_KEY, readStoredColorMode } from '$lib/utils/functions/color-mode';
+
+  const initialModeScript = createInitialModeExpression({
+    defaultMode: 'light',
+    modeStorageKey: MODE_STORAGE_KEY
+  });
+
+  $effect(() => {
+    if (!browser) {
+      return;
+    }
+
+    const storedPreference = readStoredColorMode();
+    systemPrefersMode.tracking(storedPreference === 'system');
+
+    if (storedPreference !== 'system' && userPrefersMode.current !== storedPreference) {
+      setMode(storedPreference);
+    }
+  });
+</script>
+
+<svelte:head>
+  <!-- eslint-disable-next-line svelte/no-at-html-tags -->
+  {@html initialModeScript}
+</svelte:head>
+
+<ModeWatcher defaultMode="light" disableHeadScriptInjection />