feat(timer): wire VisualTimer to tasks with notifications and persistence

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src-tauri/src/commands/mod.rs

@@ -4,5 +4,6 @@ pub mod hardware;
 pub mod history;
 pub mod models;
 pub mod tasks;
+pub mod timer;
 pub mod transcription;
 pub mod windows;

src-tauri/src/commands/timer.rs

@@ -0,0 +1,56 @@
+use serde::Serialize;
+
+use crate::AppState;
+use kon_storage::{clear_timer_state, get_timer_state, save_timer_state};
+
+/// Serialisable timer state response.
+#[derive(Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct TimerStateResponse {
+    pub task_id: String,
+    pub total_seconds: i64,
+    pub remaining_seconds: i64,
+    pub started_at: String,
+    pub paused: bool,
+}
+
+/// Save or update the active timer state.
+#[tauri::command]
+pub async fn save_timer(
+    state: tauri::State<'_, AppState>,
+    task_id: String,
+    total_seconds: i64,
+    remaining_seconds: i64,
+    paused: bool,
+) -> Result<(), String> {
+    save_timer_state(&state.db, &task_id, total_seconds, remaining_seconds, paused)
+        .await
+        .map_err(|e| e.to_string())
+}
+
+/// Retrieve the active timer state (for context restoration on app restart).
+#[tauri::command]
+pub async fn get_timer(
+    state: tauri::State<'_, AppState>,
+) -> Result<Option<TimerStateResponse>, String> {
+    let row = get_timer_state(&state.db)
+        .await
+        .map_err(|e| e.to_string())?;
+    Ok(row.map(|r| TimerStateResponse {
+        task_id: r.task_id,
+        total_seconds: r.total_seconds,
+        remaining_seconds: r.remaining_seconds,
+        started_at: r.started_at,
+        paused: r.paused,
+    }))
+}
+
+/// Clear the active timer (completed or cancelled).
+#[tauri::command]
+pub async fn clear_timer(
+    state: tauri::State<'_, AppState>,
+) -> Result<(), String> {
+    clear_timer_state(&state.db)
+        .await
+        .map_err(|e| e.to_string())
+}