feat: improve SEO with favicons, optimized OG image, and enhanced schema (#99)

* feat: improve SEO with favicons, optimized OG image, and enhanced schema

- Add favicon PNG assets (16x16, 32x32, 96x96) for better browser/Search display
- Add apple-touch-icon (180x180) for iOS devices
- Add PWA icons (192x192, 512x512) with maskable support
- Optimize OG image from 6.8MB to 279KB (1200x630px)
- Update web manifest with correct icons and theme color (#3CB371)
- Enhance JSON-LD with Organization and WebSite schemas
- Remove hardcoded version from SoftwareApplication schema
- Update sitemap lastmod to 2026-01-29 and changefreq to monthly

* fix: add back softwareVersion for CI sync

* feat: regenerate favicons with high-res transparent image

* feat: replace vocalinux.svg with vocalinux.png in web

web/public/site.webmanifest

@@ -5,7 +5,7 @@
     "start_url": "/",
     "display": "standalone",
     "background_color": "#ffffff",
-    "theme_color": "#7c3aed",
+    "theme_color": "#3CB371",
     "icons": [
         {
             "src": "/favicon-16x16.png",
@@ -17,10 +17,27 @@
             "sizes": "32x32",
             "type": "image/png"
         },
+        {
+            "src": "/favicon-96x96.png",
+            "sizes": "96x96",
+            "type": "image/png"
+        },
         {
             "src": "/apple-touch-icon.png",
             "sizes": "180x180",
             "type": "image/png"
+        },
+        {
+            "src": "/icon-192x192.png",
+            "sizes": "192x192",
+            "type": "image/png",
+            "purpose": "any maskable"
+        },
+        {
+            "src": "/icon-512x512.png",
+            "sizes": "512x512",
+            "type": "image/png",
+            "purpose": "any maskable"
         }
     ]
 }

web/public/sitemap.xml

@@ -2,8 +2,8 @@
 <urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
   <url>
     <loc>https://vocalinux.com/</loc>
-    <lastmod>2026-01-19</lastmod>
-    <changefreq>weekly</changefreq>
+    <lastmod>2026-01-29</lastmod>
+    <changefreq>monthly</changefreq>
     <priority>1.0</priority>
   </url>
 </urlset>

web/src/app/layout.tsx

@@ -48,10 +48,13 @@ export const metadata: Metadata = {
   publisher: "Vocalinux",
   icons: {
     icon: [
-      { url: "/vocalinux.svg", type: "image/svg+xml" },
+      { url: "/vocalinux.png", type: "image/png" },
+      { url: "/favicon-16x16.png", sizes: "16x16", type: "image/png" },
+      { url: "/favicon-32x32.png", sizes: "32x32", type: "image/png" },
+      { url: "/favicon-96x96.png", sizes: "96x96", type: "image/png" },
     ],
-    apple: [{ url: "/vocalinux.svg", type: "image/svg+xml" }],
-    shortcut: "/vocalinux.svg"
+    apple: [{ url: "/apple-touch-icon.png", sizes: "180x180", type: "image/png" }],
+    shortcut: "/vocalinux.png"
   },
   manifest: "/site.webmanifest",
   appleWebApp: {
@@ -104,7 +107,8 @@ export default function RootLayout({
 }: Readonly<{
   children: React.ReactNode;
 }>) {
-  const jsonLd = {
+  // SoftwareApplication schema
+  const softwareAppJsonLd = {
     "@context": "https://schema.org",
     "@type": "SoftwareApplication",
     "name": "Vocalinux",
@@ -116,7 +120,7 @@ export default function RootLayout({
       "priceCurrency": "USD"
     },
     "description": "Free, open-source voice dictation for Linux. 100% offline with Whisper AI and VOSK. Works with X11 and Wayland.",
-    "softwareVersion": "0.4.1-alpha",
+    "softwareVersion": "0.0.0",
     "author": {
       "@type": "Person",
       "name": "Jatin K Malik",
@@ -137,6 +141,47 @@ export default function RootLayout({
     ]
   };
 
+  // Organization schema
+  const organizationJsonLd = {
+    "@context": "https://schema.org",
+    "@type": "Organization",
+    "name": "Vocalinux",
+    "url": "https://vocalinux.com",
+    "logo": "https://vocalinux.com/vocalinux.png",
+    "description": "Free, open-source voice dictation for Linux",
+    "sameAs": [
+      "https://github.com/jatinkrmalik/vocalinux"
+    ],
+    "author": {
+      "@type": "Person",
+      "name": "Jatin K Malik",
+      "url": "https://github.com/jatinkrmalik"
+    }
+  };
+
+  // WebSite schema
+  const webSiteJsonLd = {
+    "@context": "https://schema.org",
+    "@type": "WebSite",
+    "name": "Vocalinux",
+    "url": "https://vocalinux.com",
+    "description": "Voice dictation for Linux, finally done right. 100% offline and privacy-focused.",
+    "potentialAction": {
+      "@type": "SearchAction",
+      "target": {
+        "@type": "EntryPoint",
+        "urlTemplate": "https://github.com/jatinkrmalik/vocalinux/issues?q={search_term_string}"
+      },
+      "query-input": {
+        "@type": "PropertyValueSpecification",
+        "valueRequired": true,
+        "valueName": "search_term_string"
+      }
+    }
+  };
+
+  const jsonLd = [softwareAppJsonLd, organizationJsonLd, webSiteJsonLd];
+
   return (
     <html lang="en" className={`${GeistSans.variable} scroll-smooth`} suppressHydrationWarning>
       <head>

web/src/app/page.tsx

@@ -195,7 +195,7 @@ export default function HomePage() {
         <nav className="max-w-7xl mx-auto px-4 sm:px-6 py-3 flex items-center justify-between">
           <Link href="/" className="flex items-center gap-2 group">
             <Image
-              src="/vocalinux.svg"
+              src="/vocalinux.png"
               alt="Vocalinux Logo"
               width={32}
               height={32}
@@ -557,7 +557,7 @@ export default function HomePage() {
                   <div className="relative">
                     <div className="bg-white dark:bg-zinc-800 rounded-2xl p-8 shadow-xl">
                       <div className="flex items-center gap-4 mb-6">
-                        <Image src="/vocalinux.svg" alt="Vocalinux" width={64} height={64} className="h-16 w-16" />
+                        <Image src="/vocalinux.png" alt="Vocalinux" width={64} height={64} className="h-16 w-16" />
                         <div>
                           <div className="text-2xl font-bold">Vocalinux</div>
                           <div className="text-sm text-muted-foreground">
@@ -1026,7 +1026,7 @@ export default function HomePage() {
           <div className="grid grid-cols-1 sm:grid-cols-2 md:grid-cols-4 gap-8 mb-12">
             <div className="md:col-span-2">
               <Link href="/" className="flex items-center gap-2 mb-4">
-                <Image src="/vocalinux.svg" alt="Vocalinux" width={32} height={32} className="h-8 w-8" />
+                <Image src="/vocalinux.png" alt="Vocalinux" width={32} height={32} className="h-8 w-8" />
                 <span className="text-xl font-bold">Vocalinux</span>
               </Link>
               <p className="text-zinc-400 mb-4 max-w-md">

web/src/components/icons.tsx

@@ -7,7 +7,7 @@ import Image from "next/image";
 export const VocalinuxLogo: React.FC<{ className?: string }> = ({ className = "" }) => {
   return (
     <Image
-      src="/vocalinux.svg"
+      src="/vocalinux.png"
       alt="Vocalinux Logo"
       width={36}
       height={36}