chore: initial project setup

- Cargo init with dependencies (ratatui, crossterm, tokio, reqwest, rusqlite, serde, chrono, dirs)
- Module structure: domain/, ui/, infrastructure/
- Domain models (TaskList, Task, TaskStatus, SyncAction, SyncQueueItem)
- .gitignore for target/ and *.db
- Rustls-based TLS (no OpenSSL dependency)

src/main.rs

@@ -0,0 +1,7 @@
+mod domain;
+mod ui;
+mod infrastructure;
+
+fn main() {
+    println!("Task App - Google Tasks TUI");
+}