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.

.gitignore

@@ -42,3 +42,34 @@ src-tauri/target/
 
 # IDE
 .idea/
+.vscode/
+
+# OS
+.DS_Store
+Thumbs.db
+
+# Secrets & certificates
+*.pem
+*.key
+*.p12
+*.pfx
+*.cer
+*.crt
+*.p8
+*.mobileprovision
+*.provisionprofile
+*.keystore
+*.jks
+*.sig
+*.asc
+*.gpg
+.env
+.env.*
+!.env.example
+
+# Logs
+*.log
+logs/
+
+# Misc
+*.blockmap