feat(tauri): add Tauri v2 Android app wrapper

- Wrap apps/web as Android APK via Tauri v2 WebView (zero web changes)
- Disable default compression feature to avoid brotli/alloc-no-stdlib conflict with Rust 1.96
- Add RGBA icon placeholders
- Add Android keystore to gitignore

APK output: apps/tauri/gen/android/app/build/outputs/apk/

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

apps/tauri/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "zeavis-edu-tauri"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+name = "zeavis_edu_tauri"
+crate-type = ["staticlib", "cdylib", "rlib"]
+
+[build-dependencies]
+tauri-build = { version = "2", features = [] }
+
+[dependencies]
+tauri = { version = "2", default-features = false, features = ["wry", "common-controls-v6", "dynamic-acl", "x11", "dbus", "custom-protocol"] }
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"