Add Tauri app backend setup with dependencies and basic build script

- Introduced `build.rs` for Tauri build process initialization.
- Added `Cargo.toml` with dependencies for Tauri plugins, serialization, cryptography, and database handling.
- Generated `Cargo.lock` to lock package versions for consistency.

src-tauri/Cargo.toml

@@ -0,0 +1,47 @@
+[package]
+name = "eritorsscribe"
+version = "0.5.0"
+description = "ERitors Scribe - Desktop app for writers"
+edition = "2021"
+
+[lib]
+name = "eritorsscribe_lib"
+crate-type = ["lib", "cdylib", "staticlib"]
+
+[build-dependencies]
+tauri-build = { version = "2", features = [] }
+
+[dependencies]
+tauri = { version = "2", features = ["devtools"] }
+tauri-plugin-shell = "2"
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
+tokio = { version = "1", features = ["full"] }
+rusqlite = { version = "0.32", features = ["bundled"] }
+aes = "0.8"
+cbc = "0.1"
+pbkdf2 = { version = "0.12", features = ["simple"] }
+sha2 = "0.10"
+hmac = "0.12"
+hex = "0.4"
+rand = "0.9"
+bcrypt = "0.17"
+hostname = "0.4"
+thiserror = "2"
+chrono = { version = "0.4", features = ["serde"] }
+base64 = "0.22"
+log = "0.4"
+dirs-next = "2"
+regex = "1"
+uuid = { version = "1", features = ["v4"] }
+reqwest = { version = "0.12", features = ["blocking", "json"] }
+docx-rs = "0.4"
+epub-builder = "0.7"
+printpdf = "0.7"
+keyring = { version = "3", features = ["apple-native", "windows-native", "sync-secret-service"] }
+sha1 = "0.10"
+tauri-plugin-http = "2.5.8"
+
+[target.'cfg(any(target_os = "macos", windows, target_os = "linux"))'.dependencies]
+tauri-plugin-process = "2.3.1"
+tauri-plugin-updater = "2.10.1"