feat: use cameleer3-logo.svg from design-system v0.1.36 everywhere

- Sidebar, sign-in page, and favicons all use the single SVG
- Postinstall copies SVG for SaaS HTML favicon (gitignored)
- Sign-in favicon committed (baked into Logto Docker image)
- Remove old PNG favicon references

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

src/main/java/net/siegeln/cameleer/saas/config/SecurityConfig.java

@@ -45,7 +45,7 @@ public class SecurityConfig {
                         .requestMatchers("/api/config").permitAll()
                         .requestMatchers("/", "/index.html", "/login", "/callback",
                                 "/environments/**", "/license", "/admin/**").permitAll()
-                        .requestMatchers("/_app/**", "/favicon.ico", "/favicon-32.png", "/favicon-192.png", "/logo.svg", "/logo-dark.svg").permitAll()
+                        .requestMatchers("/_app/**", "/favicon.ico", "/favicon.svg", "/logo.svg", "/logo-dark.svg").permitAll()
                         .anyRequest().authenticated()
                 )
                 .oauth2ResourceServer(oauth2 -> oauth2.jwt(jwt ->