Keep relayed text out of notify-send's option parser

The argv click command closed injection through the hint's value, but the
sender still handed the headline and description to notify-send bare. A
value beginning with a dash is parsed there as flags, and one shaped like
`--hint=string:omarchy-exec-argv:[...]` is read as a hint of its own --
libnotify keys hints in a hash table, so the later of two replaces the
earlier and a forged headline outranks the vector --exec built.

That is reachable without any --exec in sight: omarchy-tailscale-send
passes a single file's basename verbatim as the description, so a file
named like the hint gives its click action to whoever chose the name.

Put the headline and description behind a `--` so notify-send reads them
as text, and refuse any pass-through word carrying omarchy-exec-argv --
--exec is the only thing that may build a click command.

Co-Authored-By: Codex XHigh <noreply@openai.com>

bin/omarchy-notification-send

@@ -97,6 +97,14 @@ while (($# > 0)); do
   elif parse_omarchy_option "$@"; then
     shift "$parsed_option_args"
   else
+    # --exec is the only door to a click command. A relayed title or filename
+    # that lands here -- passthrough is the one position an untrusted value can
+    # still reach notify-send as an option -- must not be able to set the hint
+    # itself, which is the injection this transport exists to close.
+    if [[ $1 == *omarchy-exec-argv* ]]; then
+      echo "The click command hint can only be set with --exec, not passed through." >&2
+      exit 1
+    fi
     args+=("$1")
     shift
   fi
@@ -136,8 +144,11 @@ if ((exec_present)); then
   args+=("--hint=string:omarchy-exec-argv:$exec_argv_json")
 fi
 
+# `--` so notify-send reads the headline and description as text. Without it a
+# headline beginning with a dash is parsed as options ("-rf x" becomes -r), and
+# one shaped like `--hint=string:...` sets a hint of its own.
 if [[ -n $description ]]; then
-  notify-send "${args[@]}" "$headline" "$description"
+  notify-send "${args[@]}" -- "$headline" "$description"
 else
-  notify-send "${args[@]}" "$headline"
+  notify-send "${args[@]}" -- "$headline"
 fi