desktop: hash entries the same way they compare, only parse *.desktop

Desktop derived Hash over every field but PartialEq compared only the
name, violating the Hash/Eq contract the launcher's HashMap relies on
(clippy denies this by default, so `cargo clippy` failed to build).

Also skip directories and files without a .desktop extension (mimeinfo
cache, .directory files, ...) and stop unwrapping non-UTF-8 paths.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

src/utils/desktop.rs

@@ -3,7 +3,9 @@ use std::{
     collections::HashSet,
     error::Error,
     fs::{read_to_string, File},
+    hash::{Hash, Hasher},
     io::{Error as io_error, ErrorKind},
+    path::Path,
 };
 
 use serde::{self, Deserialize, Serialize};
@@ -12,7 +14,7 @@ use walkdir::WalkDir;
 
 use crate::utils::{inish, xdg};
 
-#[derive(Serialize, Deserialize, Clone, Debug, Eq, Hash)]
+#[derive(Serialize, Deserialize, Clone, Debug, Eq)]
 #[serde(rename_all = "snake_case")]
 pub struct Desktop {
     pub entry_type: String,
@@ -26,7 +28,7 @@ pub struct Desktop {
 }
 
 impl Desktop {
-    fn parse(f: &str) -> Result<Desktop, Box<dyn Error>> {
+    fn parse(f: &Path) -> Result<Desktop, Box<dyn Error>> {
         let s = read_to_string(f)?;
         let config = inish::parse(&s)?;
         match config.get("Desktop Entry") {
@@ -74,6 +76,13 @@ impl PartialEq for Desktop {
     }
 }
 
+// Must agree with PartialEq: equal entries (same name) must hash equally.
+impl Hash for Desktop {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.name.hash(state)
+    }
+}
+
 pub fn load_desktop_cache() -> Result<Vec<Desktop>, Box<dyn Error>> {
     match File::open(format!("{}/wldash/desktop.json", xdg::cache_folder())) {
         Ok(f) => simd_json::from_reader(f).map_err(|e| e.into()),
@@ -95,9 +104,15 @@ pub fn load_desktop_files() -> Vec<Desktop> {
     let mut seen: HashSet<String> = HashSet::new();
 
     for dir in dirs {
-        for entry in WalkDir::new(format!("{}/applications", dir)) {
-            if let Ok(entry) = entry {
-                if let Ok(d) = Desktop::parse(entry.path().to_str().unwrap()) {
+        for entry in WalkDir::new(format!("{}/applications", dir)).into_iter().flatten() {
+            // Entries are often symlinks, so only rule out directories.
+            if entry.file_type().is_dir()
+                || entry.path().extension().and_then(|e| e.to_str()) != Some("desktop")
+            {
+                continue;
+            }
+            {
+                if let Ok(d) = Desktop::parse(entry.path()) {
                     if d.hidden
                         || d.no_display
                         || (d.entry_type != "Application" && d.entry_type != "Link")