Top-right action strip: pin undo/redo + canvas-size readouts under Nostr widget

The undo/redo pair and the trim/sheet canvas-size pills lived inside
.topbar's flex row, which wraps at narrow widths. Adam wanted them in a
permanent, predictable place so muscle memory works regardless of
editor mode or sidebar state.

Changes:
  - .status is now `position: fixed; top: var(--top-strip-height);
    right: 0; flex-wrap: nowrap` with the same panel/border styling as
    the Nostr widget — a second strip directly below it.
  - Reordered the markup so the canvas-size pills come first and the
    undo/redo group last, so undo/redo end up hugging the viewport edge
    and the pills sit to their left (matching the requested layout).
  - Dropped the `body.app-designer .status` override (full-width
    left-aligned), since the new positioning is universal across modes.
  - updateNostrWidgetSpace() now measures the wider of the Nostr widget
    or the new strip and reserves topbar right padding accordingly, so
    the project title can't slide under the strip.

Verified via CDP at 1440px (cover, customart, pixelart modes) and at
900px narrow — strip stays pinned top-right with undo/redo on the
outside edge in every case.

Co-Authored-By: Claude Opus 4.7 <[email protected]>

TODO.md

@@ -5,8 +5,12 @@ Running list of deferred work. Detailed specs for the larger items live in
 
 ## Adam's working list
 
-_(Empty — see "Shipped (recent)" below for the items that just
-landed. Drop new items in here as they come up.)_
+- **Pixel canvas size dropdown — fix sidebar clipping.** When the
+  sidebar is open and the canvas size row wraps to a second line on
+  the left, the pixel-art canvas-size dropdown is clipped by the
+  sidebar. Easiest fix is probably "always right-align when wrapped"
+  so the dropdown opens away from the sidebar; or move the dropdown
+  to a placement that can't collide with the sidebar.
 
 ## QR code layer — remaining phases
 
@@ -84,6 +88,15 @@ Each has a full spec in `docs/`.
 
 ## Shipped (recent)
 
+- **Top-right action strip — permanent, never wraps.** Pulled the
+  canvas-size readouts and the undo / redo pair out of the topbar's
+  flex flow and pinned them in a fixed strip directly under the Nostr
+  widget, right-anchored, with `flex-wrap: nowrap`. Order: canvas-size
+  pills on the left, undo / redo on the right (so undo / redo hug the
+  viewport edge). The topbar's right padding now tracks the wider of
+  the Nostr widget or the strip via the existing
+  `--nostr-widget-space` var, so the project title never slides under
+  it.
 - **Click canvas background → deselect.** The existing #sheet click
   handler missed clicks in the gutter between sheet edge and
   previewShell edge; added a #previewShell handler.