Update to version 0.4.3 with S3 configuration improvements

- Always regenerate Museum configuration on startup to enable runtime S3 credential changes
- Improve S3 configuration logging and validation for Cloudflare R2 endpoints
- Update SMTP configuration to use SMTPS port 2465 with TLS encryption
- Fix Caddy proxy headers to properly forward client information
- Add startup.log for enhanced troubleshooting
- Update build instructions and changelog for version 0.4.3

CloudronManifest.json

@@ -7,7 +7,7 @@
   "contactEmail": "contact@ente.io",
   "website": "https://ente.io",
   "tagline": "Open source, end-to-end encrypted photo backup",
-  "version": "0.4.0",
+  "version": "0.4.3",
   "upstreamVersion": "git-main",
   "healthCheckPath": "/health",
   "httpPort": 3080,
@@ -17,7 +17,8 @@
     "localstorage": {},
     "postgresql": {},
     "sendmail": {
-      "supportsDisplayName": true
+      "supportsDisplayName": true,
+      "requiresValidCertificate": true
     }
   },
   "checklist": {