Run argv click actions through a login shell as positional params

Quickshell.execDetached(argv) ran the click target with only the shell
process's stripped environment, so GUI actions like the screenshot editor
(tensaku-edit) — resolved on the login-shell PATH the old `bash -lc` string
exec provided — stopped launching on click.

Run the argv through `bash -lc 'exec "$@"'` instead: the script text is a
constant and the arguments are passed as positional parameters, which bash
expands without re-tokenizing or re-evaluating, so injection safety is intact
while PATH and session env match the old behavior exactly.

docs/notifications.md

@@ -94,12 +94,16 @@ an action and just expect click-to-jump.
 ### Click commands must be argv, not shell strings
 
 Prefer `--exec-arg` for every click command. Each `--exec-arg` contributes one
-literal argument; the shell runs the resulting vector with
+literal argument; the shell runs the resulting vector through
-`Quickshell.execDetached(argv)` and **no shell**, so a value carrying data an
+`Util.execArgv`, which invokes `bash -lc 'exec "$@"'` with the arguments as
-attacker controls — a downloaded video's title, a received filename, a crashed
+**positional parameters** — never interpolated into the script text. bash
-process's name — is only ever a single argument and can never be reparsed as a
+expands `"$@"` without re-tokenizing or re-evaluating it, so a value carrying
-command. This is the parameterized form: pass untrusted data as its own
+data an attacker controls — a downloaded video's title, a received filename, a
-`--exec-arg` rather than quoting it into a string.
+crashed process's name — is only ever a single argument and can never be
+reparsed as a command. The login shell keeps the PATH and session environment
+that GUI click targets (the screenshot editor, mpv, xdg-open) expect. This is
+the parameterized form: pass untrusted data as its own `--exec-arg` rather than
+quoting it into a string.
 
 `--exec` is the legacy free-form variant, run through `bash -lc`. It is safe
 only when the caller shell-quoted every interpolated value perfectly — the same

shell/Commons/Util.qml

@@ -54,12 +54,17 @@ QtObject {
     Quickshell.execDetached(["bash", "-lc", command])
   }
 
-  // Run an argv vector directly, without a shell. Nothing in the array is
+  // Run an argv vector safely: the script text is the constant `exec "$@"`, so
-  // reparsed, so an argument carrying attacker-controlled data (a filename, a
+  // the arguments only ever land in bash's positional parameters, which it
-  // title) can never turn into a command. Prefer this over execDetached for any
+  // expands without re-tokenizing or re-evaluating — a value carrying
-  // command assembled from untrusted input.
+  // attacker-controlled data ($(id), a filename, a title) stays one literal
+  // argument and can never turn into a command. The login shell (-l) is what
+  // makes this a drop-in for execDetached: click actions launch GUI apps
+  // (tensaku, mpv, xdg-open) that need the same PATH and session environment the
+  // login shell set up. Prefer this over execDetached for any command assembled
+  // from untrusted input.
   function execArgv(argv) {
-    Quickshell.execDetached(argv)
+    Quickshell.execDetached(["bash", "-lc", 'exec "$@"', "bash"].concat(argv))
   }
 
   function isPlainObject(value) {

shell/plugins/notifications/NotificationLogic.js

@@ -75,7 +75,8 @@ function execFromHints(hints) {
 
 // The click action as an argv vector, sent by omarchy-notification-send
 // --exec-arg and carried as a JSON array string in the omarchy-exec-argv hint.
-// The shell runs it with Quickshell.execDetached (no shell), so a value that an
+// The shell runs it via Util.execArgv, which passes the arguments as bash
+// positional parameters rather than interpolating them, so a value that an
 // attacker controls — a video title, a filename, a URL — is only ever one
 // argument and can never be reparsed as a command. This is the parameterized
 // form: the "prepared statement" to execFromHints's string concatenation.

shell/plugins/notifications/Service.qml

@@ -361,10 +361,11 @@ Item {
     if (index < 0 || index >= popupModel.count) return
     var entry = popupModel.get(index)
 
-    // Preferred path: an argv vector run without a shell, so data an attacker
+    // Preferred path: an argv vector whose arguments are passed as bash
-    // controls (a video title, a filename) is only ever an argument and can
+    // positional parameters (never interpolated into a command), so data an
-    // never be reparsed as a command. Detached so it outlives the shell, which
+    // attacker controls (a video title, a filename) is only ever an argument and
-    // the installer toasts depend on: they restart the shell as their first act.
+    // can never be reparsed as a command. Detached so it outlives the shell,
+    // which the installer toasts depend on: they restart it as their first act.
     var argv = NotificationLogic.parseExecArgv(entry ? entry.execArgv : "")
     if (argv) {
       Util.execArgv(argv)