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/sign-in/package.json

@@ -9,7 +9,7 @@
     "preview": "vite preview"
   },
   "dependencies": {
-    "@cameleer/design-system": "0.1.34",
+    "@cameleer/design-system": "0.1.36",
     "react": "^19.0.0",
     "react-dom": "^19.0.0"
   },