Restructure upload validation env and colocate config types.

Move app config shapes under types/config, replace batch upload env vars with
per-image bytes and JSON body padding, and extend IsBase64 for decoded limits.

.env.example

@@ -18,11 +18,10 @@ NODE_ENV=development
 
 CORS_ORIGINS=http://localhost:5173,http://127.0.0.1:5173
 
-MULTER_MAX_FILE_BYTES=10485760
-
 ALTCHA_ENABLED=true
 ALTCHA_HMAC_KEY=change-me-use-long-random-secret
 ALTCHA_MAX_NUMBER=50000
+ALTCHA_CHALLENGE_TTL_MS=600000
 
 NEVER_MODE_INACTIVITY_DAYS=365
 
@@ -31,11 +30,13 @@ THROTTLE_LIMIT=1000
 THROTTLE_UPLOAD_TTL_MS=60000
 THROTTLE_UPLOAD_LIMIT=20
 
-VALIDATION_UPLOAD_MAX_IMAGES_PER_UPLOAD=10
 VALIDATION_UPLOAD_MAX_VIEWS_MAX=1000000
+VALIDATION_UPLOAD_MAX_IMAGE_BYTES=10485760 # 10MiB
+VALIDATION_UPLOAD_JSON_BODY_PADDING_BYTES=2097152 # 2MiB
 
 VITE_API_BASE_URL=http://localhost:3000/api
 VITE_CLEARNET_DOMAIN=localhost:5173
 VITE_ONION_HOSTNAME=
-VITE_VALIDATION_UPLOAD_MAX_IMAGES_PER_UPLOAD=10
+VITE_UPLOAD_MAX_QUEUE_SIZE=10
 VITE_VALIDATION_UPLOAD_MAX_VIEWS_MAX=1000000
+VITE_VALIDATION_UPLOAD_MAX_IMAGE_BYTES=10485760 # 10MiB