feat: v0.3.0 re-release - add dashboard & sessions, hide pi option

- Usage dashboard: KPIs, model split, daily bars, year heatmap, recent requests
- Sessions management: list/preview/archive/delete with streaming preview
- Double-click daily bar opens per-model breakdown modal
- Paginated recent requests (30/page)
- Hide pi option from nav (kept code, just removed from UI)
- Timezone fixes: today/day_key/heatmap now use local calendar day
- Streaming preview with 20MB byte cap + 500-char frontend clip
- README attribution to kimicode-dashboard (MIT, JochenYang)

src-tauri/src/lib.rs

@@ -1,5 +1,6 @@
 pub mod commands;
 pub mod config_io;
+pub mod dashboard;
 pub mod db;
 pub mod kimi_code_io;
 pub mod models;
@@ -99,6 +100,15 @@ pub fn run() {
             commands::get_app_version,
             commands::list_provider_models,
             commands::debug_log,
+            dashboard::get_paths,
+            dashboard::get_prices,
+            dashboard::get_summary,
+            dashboard::list_sessions,
+            dashboard::archive_session,
+            dashboard::unarchive_session,
+            dashboard::delete_session,
+            dashboard::delete_workspace,
+            dashboard::get_session_preview,
         ])
         .run(tauri::generate_context!())
         .expect("error while running tauri application");