fix: use full-color brand PNGs for login dialog and sidebar

The SVG uses fill=currentColor (inherits text color). Switch to the
full-color PNG brand icons: 192px for login dialog, 48px for sidebar.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

cameleer3-server-app/src/main/java/com/cameleer3/server/app/security/SecurityConfig.java

@@ -95,6 +95,7 @@ public class SecurityConfig {
                                 "/index.html",
                                 "/config.js",
                                 "/favicon-*.png",
+                                "/cameleer3-logo-*.png",
                                 "/camel-logo.svg",
                                 "/assets/**"
                         ).permitAll()

ui/src/auth/LoginPage.tsx

@@ -131,7 +131,7 @@ export function LoginPage() {
       <Card className={styles.card}>
         <div className={styles.loginForm}>
           <div className={styles.logo}>
-            <img src={`${config.basePath}camel-logo.svg`} alt="" className={styles.logoImg} />
+            <img src={`${config.basePath}cameleer3-logo-192.png`} alt="" className={styles.logoImg} />
             cameleer3
           </div>
           <p className={styles.subtitle}>{subtitle}</p>

ui/src/components/LayoutShell.tsx

@@ -625,7 +625,7 @@ function LayoutContent() {
 
   // --- Render -------------------------------------------------------
   const camelLogo = (
-    <img src={`${config.basePath}camel-logo.svg`} alt="" style={{ width: 28, height: 24 }} />
+    <img src={`${config.basePath}cameleer3-logo-48.png`} alt="" style={{ width: 28, height: 28 }} />
   );
 
   const sidebarElement = (