desktop: version 0.1.0 -> 0.2.8.2, into the lockstep

desktop sat at the 0.1.0 stub while everything else moved to 0.2.8.2, so the
release gate's version lockstep would reject any tag. bump-version.sh already
covers desktop (steps 5/6) — this is the one-time catch-up it couldn't do as a
no-op. Cargo.toml 3-part (0.2.8), tauri.conf.json 4-octet (0.2.8.2).

desktop/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "redflag-desktop"
-version = "0.1.0"
+version = "0.2.8"
 edition = "2021"
 publish = false
 

desktop/tauri.conf.json

@@ -1,7 +1,7 @@
 {
   "$schema": "https://schema.tauri.app/config/2",
   "productName": "RedFlag",
-  "version": "0.1.0",
+  "version": "0.2.8.2",
   "identifier": "com.redflag.local",
   "build": {
     "beforeDevCommand": "npm --prefix ../web run dev:desktop",