0.2.3 — built-in code editor, .uasset previews, new icon

- Built-in code editor: edit working-copy source files in place (Edit → textarea
  → Save) before committing, no external IDE needed. Backend write_depot opens
  the file for edit, clears read-only, writes UTF-8; confined to the client root.
- .uasset previews: pull the embedded Unreal thumbnail (PNG) server-side for both
  working copy and history; on-demand real 3D via a headless Unreal FBX export
  (commandlet mode, no editor window), temp file deleted right after — nothing
  cached on disk. Plugin content paths mapped to their mount point.
- New app icon (brand mark on a theme tile) + theme-aware in-app logo.
- Connection pill / Settings show the actual connected server (P4PORT), not the
  server's internal self-reported address.
- Fix: the "select all" checkbox no longer renders as a giant empty square when
  not everything is selected (size pinned).
- IDE picker chooses which installed editor opens code; AI replies in UI language.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src-tauri/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "exbyte-depot"
-version = "0.2.2"
+version = "0.2.3"
 description = "Exbyte Depot — native Perforce client by Exbyte Studios"
 authors = ["Exbyte Studios"]
 edition = "2021"