feat: add task creation, deletion, and modal focus restoration

Implemented task creation flow with keyboard shortcut (c) and UI button. Added task deletion with confirmation dialog,
accessible via Delete key or per-row delete button. Fixed modal close behavior to restore
focus and reselect the appropriate task (created task for new tasks, original task for view/edit).
Enhanced tag and project autocomplete with hierarchical project suggestions and tag filtering

src/view/task_detail_modal/render/mod.rs

@@ -45,6 +45,7 @@ pub(super) fn render_task_detail_modal(
         panel::render_task_detail_panel(
             detail,
             state.mode,
+            state.is_create,
             state.edit_state,
             &state.form,
             &state.errors,