feat: Armarium full customization and 4-language i18n (v0.8.0)

Replaces Astro Rocket demo content with Armarium branding and adds
complete DE/FR/IT/EN translations across all pages.

Branding & content (v0.7.0):
- Add horizontal SVG logo to navbar with currentColor dark mode support
- Rewrite homepage with Armarium hero, 6 feature cards, trust bar,
  Zürich coat of arms SVG, and CTA; shared HomePage.astro component
- Add privacy page (/datenschutz) with 6 Infomaniak certification cards
  and 8-section policy (ISO 27001:2022, Swiss Hosting, nDSG/GDPR, etc.)
- Add legal notice page (/impressum)
- Rewrite about, contact, 404 pages with Armarium content
- Add features page (/projects) from projects content collection
- Add language switcher dropdown (LanguageSwitcherDropdown.astro)
- Add single launch blog post; remove all demo blog/project content
- Set up i18n foundation: astro.config.mjs, ui.ts, utils.ts

Full i18n (v0.8.0):
- Add all pages in FR/IT/EN: about, contact, blog, features, privacy,
  legal notice — 28 locale variants total
- Language switcher visible in every layout (PageLayout, BlogLayout,
  ProjectLayout, LandingLayout) with translated nav items
- Locale-aware nav and footer hrefs via nav.*.href keys in ui.ts
- Shared page components (AboutPage, ContactPage, FeaturesIndexPage,
  BlogIndexPage) accept locale prop; locale pages are 4-line wrappers
- Extend content.config.ts locale enum with de and it

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

src/components/layout/Header.astro

@@ -31,7 +31,9 @@ import Logo from '@/components/ui/marketing/Logo/Logo.astro';
 import ThemeToggle from '@/components/layout/ThemeToggle.astro';
 import ThemeSelector from '@/components/layout/ThemeSelector.astro';
 import ThemeSelectorDropdown from '@/components/layout/ThemeSelectorDropdown.astro';
+import LanguageSwitcherDropdown from '@/components/layout/LanguageSwitcherDropdown.astro';
 import siteConfig from '@/config/site.config';
+import type { Locale } from '@/i18n/ui';
 
 export interface NavItem {
   label: string;
@@ -83,6 +85,8 @@ interface Props extends HTMLAttributes<'header'> {
   hideLogo?: boolean;
   /** Show language switcher */
   showLanguageSwitcher?: boolean;
+  /** Current locale for language switcher */
+  currentLocale?: Locale;
   /** Show social icon links (desktop/tablet only, reads from siteConfig.socialLinks) */
   showSocialLinks?: boolean;
   /** Show scroll progress bar at the bottom of the header */
@@ -110,6 +114,8 @@ const {
   showActiveState = true,
   showScrollProgress = false,
   scrollProgressPosition = 'bottom',
+  showLanguageSwitcher = false,
+  currentLocale = 'de',
   logoText,
   hideLogo = false,
   class: className,
@@ -190,16 +196,13 @@ const buttonId = `${menuId}-button`;
         (hasLogoSlot ? (
           <slot name="logo" />
         ) : (
-          <a href="/" class="flex items-center gap-2">
-            <Logo size={size === 'lg' ? 'lg' : 'md'} forceDark={isInvert} />
-            <span
-              class={cn(
-                'font-display text-xl font-bold tracking-tight',
-                isFloating ? 'hdr-logo-text' : (isInvert ? 'text-on-invert' : 'text-brand-500')
-              )}
-            >
-              {logoText || siteConfig.name}
-            </span>
+          <a href="/" class="flex items-center">
+            <Logo
+              variant="full"
+              size={size === 'lg' ? 'lg' : 'md'}
+              forceDark={isInvert}
+              class={cn(isFloating ? 'hdr-logo-text' : (isInvert ? 'text-on-invert' : 'text-foreground'))}
+            />
           </a>
         ))
     }
@@ -254,6 +257,12 @@ const buttonId = `${menuId}-button`;
               </div>
             )}
 
+            {showLanguageSwitcher && (
+              <div class="hidden md:flex">
+                <LanguageSwitcherDropdown currentLocale={currentLocale as Locale} />
+              </div>
+            )}
+
             {showSocialLinks && siteConfig.socialLinks.length > 0 && (
               <div class="hidden md:flex items-center gap-0.5">
                 {siteConfig.socialLinks.map((url) => {
@@ -416,6 +425,15 @@ const buttonId = `${menuId}-button`;
                 </div>
               </div>
             )}
+
+            {showLanguageSwitcher && (
+              <div class="border-border mt-3 border-t pt-3">
+                <div class="flex items-center justify-between px-1">
+                  <span class="text-sm text-foreground-muted">Language</span>
+                  <LanguageSwitcherDropdown currentLocale={currentLocale as Locale} />
+                </div>
+              </div>
+            )}
           </div>
         </div>
       ))