feat: user avatar as public asset

Cargo.lock

@@ -879,6 +879,12 @@ version = "0.4.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7f24254aa9a54b5c858eaee2f5bccdb46aaf0e486a595ed5fd8f86ba55232a70"
 
+[[package]]
+name = "hex-literal"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6fe2267d4ed49bc07b63801559be28c718ea06c4738b7a03c94df7386d2cde46"
+
 [[package]]
 name = "hkdf"
 version = "0.12.4"
@@ -1256,9 +1262,11 @@ dependencies = [
  "dotenvy",
  "env_logger",
  "fully_pub",
+ "hex-literal",
  "log",
  "serde",
  "serde_json",
+ "sha2",
  "sqlx",
  "strum",
  "strum_macros",