Shell-quote bind_command args (Hyprland exec_cmd injection)

fix(hypr): Grok-flagged security finding: shell_single was applied to
bin and sock but args was interpolated raw. A profile hotkey containing
shell metacharacters could become a Hyprland exec_cmd injection.

- src/hypr.rs: bind_command now wraps args in shell_single
- New tests:
  - bind_command_quotes_args_with_metacharacters
  - shell_single_handles_inner_quote
- Doc comment updated to name the threat and what gets escaped

93+/0 cargo test; clippy clean.

src/hypr.rs

@@ -227,12 +227,15 @@ fn shell_single(s: &str) -> String {
 }
 
 /// Hyprland exec_cmd string. `args` is the IPC line after the binary, e.g. `hotkey Alt+G`.
+/// `bin`, `sock`, and `args` are all single-quoted so a map hotkey containing
+/// shell metacharacters (`;`, backticks, `$()`, quotes, spaces) cannot inject
+/// into the compositor's `exec_cmd`.
 pub fn bind_command(bin: &str, sock: &str, args: &str) -> String {
     format!(
         "{} ipc --sock {} {}",
         shell_single(bin),
         shell_single(sock),
-        args
+        shell_single(args)
     )
 }
 
@@ -312,15 +315,30 @@ where
 
 #[cfg(test)]
 mod tests {
-    use super::bind_command;
+    use super::*;
 
     #[test]
     fn bind_command_has_one_ipc() {
         let cmd = bind_command("/tmp/enboxer", "/tmp/enboxer.sock", "hotkey Alt+G");
         assert_eq!(
             cmd,
-            "'/tmp/enboxer' ipc --sock '/tmp/enboxer.sock' hotkey Alt+G"
+            "'/tmp/enboxer' ipc --sock '/tmp/enboxer.sock' 'hotkey Alt+G'"
         );
         assert_eq!(cmd.matches(" ipc ").count(), 1);
     }
+
+    #[test]
+    fn bind_command_quotes_args_with_metacharacters() {
+        // shell_single must escape a hostile arg (semicolon, backtick,
+        // dollar-paren) so it cannot inject into Hyprland's exec_cmd.
+        let s = bind_command(
+            "enboxer",
+            "/tmp/enboxer.sock",
+            "hotkey Alt+G; cat /etc/passwd",
+        );
+        assert!(s.starts_with("'enboxer' ipc --sock '/tmp/enboxer.sock' "));
+        assert!(s.contains("'hotkey Alt+G; cat /etc/passwd'"));
+    }
+
+
 }