Added Oxibadge, a minimal Tauri + Svelte desktop client

Scaffolds the oxibadge crate/frontend as a new workspace member, stripped
down to a bare hello-world, and
extends the CI pipeline

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

Cargo.toml

@@ -1,8 +1,16 @@
 [workspace]
 resolver = "3"
-members = ["r701"]
+members = ["r701", "oxibadge/src-tauri"]
 
 [workspace.package]
 edition = "2021"
 license = "AGPL-3.0-or-later"
 repository = "https://git.nicolabelluti.me/nicolabelluti/r701"
+
+# Read the optimization guideline for more details: https://tauri.app/concept/size/#cargo-configuration
+[profile.release]
+codegen-units = 1
+lto = true
+opt-level = 3
+panic = "abort"
+strip = true