refactor: update Nginx configuration and Docker setup

- Change user directive in Nginx configuration from 'nginx' to 'www-data'.
- Update upstream server configurations in Nginx to use 'localhost' instead of service names.
- Modify Nginx server block to redirect HTTP to a status page instead of Grafana.
- Rename Alertmanager location from '/alertmanager/' to '/alerts/' for consistency.
- Remove deprecated status page configuration and related files.
- Adjust Prometheus configuration to reflect the new Docker network settings.

infra/nginx/conf.d/alertmanager.conf

@@ -2,12 +2,12 @@
 # Proxies requests to Alertmanager
 
 # Alertmanager location
-location /alertmanager/ {
+location /alerts/ {
     # Rate limiting
     limit_req zone=api burst=10 nodelay;
     
     # Remove trailing slash for proxy
-    rewrite ^/alertmanager/(.*)$ /$1 break;
+    rewrite ^/alerts/(.*)$ /$1 break;
     
     # Proxy to Alertmanager
     proxy_pass http://alertmanager_backend;

infra/nginx/conf.d/grafana.conf

@@ -1,6 +1,6 @@
 # Grafana proxy configuration
 location /grafana/ {
-    proxy_pass http://grafana_backend/;
+    proxy_pass http://grafana_backend;
     proxy_set_header Host $host;
     proxy_set_header X-Real-IP $remote_addr;
     proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

infra/nginx/conf.d/status.conf

@@ -1,43 +0,0 @@
-# Status page configuration (Uptime Kuma integration)
-
-# Rate limiting for status page
-location /status {
-    # Rate limiting
-    limit_req zone=status burst=5 nodelay;
-    
-    # Proxy to Uptime Kuma
-    proxy_pass http://uptime_kuma_backend;
-    proxy_set_header Host $host;
-    proxy_set_header X-Real-IP $remote_addr;
-    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
-    proxy_set_header X-Forwarded-Proto $scheme;
-    
-    # WebSocket support
-    proxy_http_version 1.1;
-    proxy_set_header Upgrade $http_upgrade;
-    proxy_set_header Connection "upgrade";
-    
-    # Timeouts
-    proxy_connect_timeout 30s;
-    proxy_send_timeout 30s;
-    proxy_read_timeout 30s;
-    
-    # Buffer settings
-    proxy_buffering on;
-    proxy_buffer_size 4k;
-    proxy_buffers 8 4k;
-    
-    # Security headers
-    add_header X-Frame-Options "SAMEORIGIN" always;
-    add_header X-Content-Type-Options "nosniff" always;
-}
-
-# Nginx status stub (for monitoring)
-location /nginx_status {
-    stub_status on;
-    access_log off;
-    allow 127.0.0.1;
-    allow 172.16.0.0/12;  # Docker networks
-    allow 192.168.0.0/16; # Private networks
-    deny all;
-}

infra/nginx/conf.d/uptime-kuma.conf

@@ -1,12 +1,6 @@
 # Uptime Kuma Nginx Configuration
 # Proxies requests to Uptime Kuma status page
 
-# Upstream for Uptime Kuma
-upstream uptime_kuma_backend {
-    server uptime-kuma:3001;
-    keepalive 32;
-}
-
 # Status page location
 location /status {
     # Rate limiting