Configurable UI - Custom Inventory Layout with Web Editor | 可自定义物品栏 UI

# Configurable UI v1.1.0 — Changelog

## Added
- **Undo / Redo in the web editor** (Ctrl+Z / Ctrl+Y, or the ↶ ↷ buttons). Covers slot drags,
  button/stat-bar/player drags, field edits, asset uploads, group/screen/button create & delete,
  and canvas resizing. Slider drags and multi-keystroke text edits collapse into single steps.
- **Grid Arrange tool** — arrange any slot group into a tidy grid (columns + gap) with one click,
  anchored at the group's first slot. No more dragging 27 inventory slots by hand.
- **Arrow-key nudging** — fine-tune the selected slot / button / stat bar with the arrow keys;
  hold Shift for 1-px precision.
- **Duplicate screens** — one-click deep copy of an independent screen (groups + per-page
  positions) with an auto-generated unique id, so page variants are cheap to build.
- **Duplicate buttons** — Ctrl+D now also duplicates the selected button.
- **Unsaved-changes protection** — the header shows a "● unsaved" indicator and the browser warns
  before closing the tab with unsaved edits.
- **Live client-window sync (WYSIWYG)** — the editor polls the client's GUI-scaled window size
  every 4 s. If the canvas drifts out of sync (GUI Scale change, window resize), a ⚠ button
  appears in the toolbar for one-click resync. Opening a fullscreen layout auto-syncs and
  auto-fits the view; minimized windows (0-size) are ignored instead of wrecking the layout.
- **Bundled default textures** — the mod now ships built-in `slot.png` (frame) and
  `background.png` fallbacks, so slots and backgrounds render out of the box before any custom
  images are uploaded.

## Fixed
- **Client crash with non-ASCII texture names** — referencing an uploaded image with a Chinese
  (or any ResourceLocation-invalid) filename could crash the game during rendering
  (ResourceLocationException). The fallback path is now validated and returns null safely.
- **GBK-encoded ZIP archives failed to load** — image archives zipped by Chinese-locale Windows
  tools store entry names in GBK; extraction now automatically retries with the GBK charset so
  those archives (e.g. `豆包.png`) load correctly.
- **Scroll speed on independent screens** — the scroll wheel step was applied in canvas pixels
  without the layout scale, producing wrong scroll speed on any non-1:1 canvas. It now scales
  correctly.
- **Screen preview now matches the game** — in-game, independent screens render all custom
  buttons; the editor's screen preview hid them. Preview and game are now consistent.
- **Undo stack pollution** — non-mutating controls (preview selector, snap pickers) no longer
  create empty undo steps; asset/picker/background changes and window syncs are now undoable.
- **Editor server memory safety** — layout POSTs are capped at 5 MiB and uploads at 10 MiB
  (HTTP 413 on overflow) instead of reading unbounded request bodies into memory.

## Changed
- Added the author's CurseForge page as the mod's display URL (shown in the mod list).