Fix second audit findings and restore crash detection dialog

src/config.rs

@@ -1,4 +1,25 @@
+use std::path::PathBuf;
+
 pub const APP_ID: &str = "app.driftwood.Driftwood";
 pub const VERSION: &str = env!("CARGO_PKG_VERSION");
 pub const GSETTINGS_SCHEMA_DIR: &str = env!("GSETTINGS_SCHEMA_DIR");
 pub const SYSTEM_APPIMAGE_DIR: &str = "/opt/appimages";
+
+/// Return the XDG data directory with a proper $HOME-based fallback.
+/// Unlike `PathBuf::from("~/.local/share")`, this actually resolves to the
+/// user's home directory instead of creating a literal `~` path.
+pub fn data_dir_fallback() -> PathBuf {
+    dirs::data_dir().unwrap_or_else(|| home_dir().join(".local/share"))
+}
+
+/// Return the XDG config directory with a proper $HOME-based fallback.
+#[allow(dead_code)]
+pub fn config_dir_fallback() -> PathBuf {
+    dirs::config_dir().unwrap_or_else(|| home_dir().join(".config"))
+}
+
+fn home_dir() -> PathBuf {
+    dirs::home_dir()
+        .or_else(|| std::env::var("HOME").ok().map(PathBuf::from))
+        .unwrap_or_else(|| PathBuf::from("/tmp"))
+}