fix(window-restore): re-read workspace/window state after the wofi pick

The picker blocks on user input for however long they take. In that
window niri can destroy a dynamic workspace (its last window closed)
and renumber every later one down, so the pre-pick current["idx"] can
point at the wrong workspace by the time move-window-to-workspace
runs — restoring to the wrong place. The stashed window itself can
also have closed in the meantime, in which case the move/focus calls
would silently no-op. main() now re-reads workspaces/windows after
pick() returns, recomputes the current workspace, and confirms the
chosen window still exists before acting; each bails with a notify
and the documented exit code otherwise. Adds window_exists() as a
pure, tested helper alongside the existing pure functions.

Also: clarify the focus=false comment in niri/config.kdl (it read as
if focus=false caused the problem it actually prevents), and note in
the design doc's Out of scope section that the stash's index-1
pinning is per-output, so a second monitor would need its own
analysis of the Mod+1..9 offset.

docs/superpowers/specs/2026-07-16-niri-minimize-design.md

@@ -226,3 +226,7 @@ the stash holds index 1).
 - Restoring to a window's *original* workspace. Rejected during design: it needs
   per-window origin tracking that can go stale.
 - A waybar module showing a stash count — the workspace pill already signals it.
+- Multi-monitor correctness: the stash is pinned to index 1 only on its own
+  output, so a second monitor's workspaces would start at 1 with no stash,
+  throwing off the `Mod+1..9` +1 offset there. Correct on this single-panel
+  (`eDP-1`) machine; latent if a second output is ever attached.

niri/config.kdl

@@ -110,8 +110,8 @@ binds {
 
     Mod+Print { spawn "screenshot"; }
 
-    // focus=false or focus follows the window into the stash — the opposite of
+    // focus=false is required here — otherwise focus follows the window into
-    // minimizing.
+    // the stash, the opposite of minimizing.
     Mod+M { move-window-to-workspace "minimized" focus=false; }
     Mod+Shift+M { spawn "window-restore"; }
 

scripts/tests/window-restore.test.py

@@ -78,6 +78,11 @@ DUPES = [
 ]
 check("duplicate labels resolve to the first", wr.resolve(DUPES, "Alacritty — same")["id"], 20)
 
+# --- window_exists -----------------------------------------------------------
+check("window_exists is True for a present window", wr.window_exists(WINDOWS, 11), True)
+check("window_exists is False once the window has closed", wr.window_exists(WINDOWS, 999), False)
+check("window_exists is False for an empty list", wr.window_exists([], 11), False)
+
 # --- pick ------------------------------------------------------------------
 check("pick returns the chooser's selection",
       wr.pick(["a", "b"], lambda text: "b"), "b")

scripts/window-restore.py

@@ -50,6 +50,13 @@ def resolve(windows, chosen):
     return next((w for w in windows if label(w) == chosen), None)
 
 
+def window_exists(windows, window_id):
+    """Whether window_id is still present in a fresh `windows` list. Used after
+    the picker returns, since wofi can block long enough for the chosen window
+    to have closed out from under us."""
+    return any(w.get("id") == window_id for w in windows)
+
+
 def pick(labels, chooser):
     """chooser(text) -> selected line. Injected so tests need no wofi."""
     return chooser("\n".join(labels))
@@ -140,6 +147,30 @@ def main():
     if window is None:
         return 0
 
+    # wofi may have sat open for however long the user took. In that time niri
+    # can destroy a dynamic workspace (its last window closed) and renumber
+    # every later one down, so the pre-pick `current["idx"]` may now name the
+    # wrong workspace; the stashed window may also have closed. Re-read state
+    # rather than trust anything captured before pick() blocked.
+    workspaces = niri_json("workspaces")
+    if workspaces is None:
+        notify("niri IPC unavailable")
+        return 1
+
+    current = current_workspace(workspaces)
+    if current is None:
+        notify("no focused workspace")
+        return 1
+
+    windows = niri_json("windows")
+    if windows is None:
+        notify("niri IPC unavailable")
+        return 1
+
+    if not window_exists(windows, window["id"]):
+        notify("that window closed before it could be restored")
+        return 0
+
     # The window is not focused (it is in the stash), so --focus does not apply;
     # focus it explicitly afterwards.
     niri_action("move-window-to-workspace", "--window-id", str(window["id"]),