refactor: use project-local data/ directory for MMDB in local dev

.env.example

@@ -1,8 +1,8 @@
 # Server listen address
 LISTEN_ADDR=0.0.0.0:3000
 
-# Path to the MaxMind DB file
-DB_PATH=/data/Merged-IP.mmdb
+# Path to the MaxMind DB file (use data/Merged-IP.mmdb for local development)
+DB_PATH=data/Merged-IP.mmdb
 
 # URL to download the MMDB database from
 DB_UPDATE_URL=https://github.com/NetworkCats/Merged-IP-Data/releases/latest/download/Merged-IP.mmdb

.gitignore

@@ -23,6 +23,7 @@ ehthumbs_vista.db
 
 # Project
 *.mmdb
+data/
 .env
 haproxy/certs/
 

tests/integration.rs

@@ -8,16 +8,17 @@ use rustyip::db;
 use rustyip::handlers::AppState;
 use rustyip::routes::build_router;
 
-fn test_db_path() -> &'static str {
-    let path = "/tmp/Merged-IP.mmdb";
-    if !Path::new(path).exists() {
+fn test_db_path() -> String {
+    let manifest_dir = env!("CARGO_MANIFEST_DIR");
+    let path = format!("{manifest_dir}/data/Merged-IP.mmdb");
+    if !Path::new(&path).exists() {
         panic!("Test MMDB not found at {path}. Download it first.");
     }
     path
 }
 
 fn build_test_app() -> axum::Router {
-    let reader = db::load_db(Path::new(test_db_path())).expect("failed to load test DB");
+    let reader = db::load_db(Path::new(&test_db_path())).expect("failed to load test DB");
     let shared_db = db::new_shared(reader);
     let state = AppState {
         db: shared_db,