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/domain/mod.rs

@@ -0,0 +1 @@
+pub mod models;

src/domain/models.rs

@@ -0,0 +1,43 @@
+use chrono::NaiveDateTime;
+use serde::{Deserialize, Serialize};
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct TaskList {
+    pub id: String,
+    pub title: String,
+}
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct Task {
+    pub id: String,
+    pub list_id: String,
+    pub title: String,
+    pub notes: Option<String>,
+    pub status: TaskStatus,
+    pub due: Option<NaiveDateTime>,
+    pub position: i64,
+}
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub enum TaskStatus {
+    NeedsAction,
+    Completed,
+}
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub enum SyncAction {
+    Create,
+    Update,
+    Delete,
+    Reorder,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct SyncQueueItem {
+    pub id: i64,
+    pub action: SyncAction,
+    pub task_id: String,
+    pub list_id: String,
+    pub payload: String,
+    pub created_at: String,
+}