fix(docker): crash loop fallback и observer-web на IFT

fallback: default_type вне if-блока nginx. observer-web: Hex/deps.compile в образе, без dev-watchers в контейнере.

docker/fallback/default.conf

@@ -2,16 +2,15 @@ server {
     listen 80 default_server;
     root /usr/share/nginx/html;
 
-    location / {
-        set $json 0;
-        if ($uri ~* "^/v1/") { set $json 1; }
-        if ($http_accept ~* "application/json") { set $json 1; }
+    location ~ ^/v1/ {
+        default_type application/json;
+        return 503 '{"error":"Service Unavailable","message":"EventHub is temporarily unavailable. Please try again later."}';
+    }
 
-        if ($json = 1) {
-            default_type application/json;
+    location / {
+        if ($http_accept ~* "application/json") {
             return 503 '{"error":"Service Unavailable","message":"EventHub is temporarily unavailable. Please try again later."}';
         }
-
         return 503;
     }
 
@@ -19,4 +18,4 @@ server {
     location = /503.html {
         internal;
     }
-}
+}