Multi-arch release script + Gitea workflow; retire legacy BunSCP name

bun run release -- --target mac-arm64|mac-x64|win-x64: gen version/icons,
build UI, electrobun build --env=stable, collect artifacts as
release/<target>/miniSCP-Build<n>-<target>.*. mac-x64 builds on the
arm64 Mac by running electrobun's x64 CLI under Rosetta 2 (verified:
x86_64 launcher in the produced app). Windows also zips a portable
build next to the Setup installer. Tag-triggered Gitea Actions matrix
included, inert until runners exist. legacyNames emptied — the BunSCP
migration has served its purpose.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/shared/branding.ts

@@ -5,9 +5,9 @@ import { BUILD } from "./version.gen";
 export const BRANDING = {
 	appName: "miniSCP",
 	identifier: "es.teknes.miniscp",
-	// Previous app names: their app-data folders are migrated on boot
+	// Previous app names whose app-data folders migrate on boot after a rename
 	// (see migrateLegacyDataDir in src/bun/store/paths.ts).
-	legacyNames: ["BunSCP"],
+	legacyNames: [] as string[],
 	// Sublime-style versioning: n = commit count (scripts/gen-version.ts).
 	// `version` stays semver-shaped for electrobun's config/updater.
 	version: `0.1.${BUILD.number}`,