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>

ui/package.json

@@ -7,10 +7,10 @@
     "dev": "vite",
     "build": "tsc -b && vite build",
     "preview": "vite preview",
-    "postinstall": "node -e \"const fs=require('fs'),p='node_modules/@cameleer/design-system/assets/';if(fs.existsSync('public')){[['cameleer3-32.png','public/favicon-32.png'],['cameleer3-192.png','public/favicon-192.png']].forEach(([s,d])=>fs.copyFileSync(p+s,d))}\""
+    "postinstall": "node -e \"const fs=require('fs'),p='node_modules/@cameleer/design-system/assets/';if(fs.existsSync('public')){fs.copyFileSync(p+'cameleer3-logo.svg','public/favicon.svg')}\""
   },
   "dependencies": {
-    "@cameleer/design-system": "0.1.34",
+    "@cameleer/design-system": "0.1.36",
     "@logto/react": "^4.0.13",
     "@tanstack/react-query": "^5.90.0",
     "lucide-react": "^1.7.0",