fix: install default Rustls crypto provider to prevent TLS initialization error

Install ring-based crypto provider at startup to fix Rustls TLS initialization error

Cargo.lock

@@ -2957,6 +2957,7 @@ dependencies = [
  "mail-parser",
  "reqwest",
  "rusqlite",
+ "rustls",
  "rustls-pki-types",
  "serde",
  "serde_json",

Cargo.toml

@@ -66,6 +66,7 @@ futures-util = { version = "0.3", default-features = false, features = ["sink"]
 hostname = "0.4.2"
 lettre = { version = "0.11.19", default-features = false, features = ["builder", "smtp-transport", "rustls-tls"] }
 mail-parser = "0.11.2"
+rustls = "0.23"
 rustls-pki-types = "1.14.0"
 tokio-rustls = "0.26.4"
 webpki-roots = "1.0.6"

src/main.rs

@@ -255,6 +255,13 @@ enum IntegrationCommands {
 #[tokio::main]
 #[allow(clippy::too_many_lines)]
 async fn main() -> Result<()> {
+    // Install default crypto provider for Rustls TLS.
+    // This prevents the error: "could not automatically determine the process-level CryptoProvider"
+    // when both aws-lc-rs and ring features are available (or neither is explicitly selected).
+    if let Err(e) = rustls::crypto::ring::default_provider().install_default() {
+        eprintln!("Warning: Failed to install default crypto provider: {e:?}");
+    }
+
     let cli = Cli::parse();
 
     // Initialize logging