feat: implement Nginx service with upstream management and configuration generation

apps/api/src/services/nginx/traits/indentable.rs

@@ -0,0 +1,31 @@
+pub trait Indentable<T> {
+    fn indent(&self, spaces: T) -> String;
+}
+
+impl Indentable<usize> for &str {
+    fn indent(&self, spaces: usize) -> String {
+        let indent_str = " ".repeat(spaces);
+        self.lines()
+            .map(|line| format!("{}{}", indent_str, line))
+            .collect::<Vec<String>>()
+            .join("\n")
+    }
+}
+
+impl Indentable<Option<usize>> for String {
+    fn indent(&self, spaces: Option<usize>) -> String {
+        self.as_str().indent(spaces.unwrap_or(0))
+    }
+}
+
+impl Indentable<usize> for String {
+    fn indent(&self, spaces: usize) -> String {
+        self.as_str().indent(spaces)
+    }
+}
+
+impl Indentable<Option<usize>> for &str {
+    fn indent(&self, spaces: Option<usize>) -> String {
+        self.indent(spaces.unwrap_or(0))
+    }
+}