fix: sqlite ?mode=rwc, remove redundant libsqlite3-sys dep

Cargo.lock

@@ -941,6 +941,7 @@ dependencies = [
  "axum",
  "chrono",
  "futures",
+ "libsqlite3-sys",
  "rumqttc",
  "rust-embed",
  "serde",

src/main.rs

@@ -192,9 +192,20 @@ async fn main() {
     let db_path = std::env::var("NEWSBOARD_DB")
         .unwrap_or_else(|_| "/var/lib/newsboard/news.db".into());
 
+    let db_path = std::env::var("NEWSBOARD_DB")
+        .unwrap_or_else(|_| "/var/lib/newsboard/news.db".into());
+
+    let url = if db_path == ":memory:" || db_path == "" {
+        "sqlite::memory:".to_string()
+    } else {
+        format!("sqlite:{}?mode=rwc", db_path)
+    };
+
+    tracing::info!(url = %url, "connecting to database");
+
     let pool = SqlitePoolOptions::new()
         .max_connections(5)
-        .connect(&format!("sqlite:{db_path}"))
+        .connect(&url)
         .await
         .expect("Failed to connect to SQLite");