feat: add theme provider and control components for light/dark mode

- Implemented ThemeProvider to manage theme state and preferences.
- Added ThemeControl component for users to switch between system, light, and dark themes.
- Integrated localStorage for theme preference persistence.
- Updated document styles based on theme changes.

test: add tests for permanent deletion of habits and related records

- Created tests to ensure permanent deletion of habits removes all dependent records.
- Verified that deletion requires ownership, authentication, and checks for archived habits.
- Added tests to confirm rollback behavior on deletion failures.

test: add tests for habit palette and progress card functionality

- Implemented tests for habit color progression and theme-based color shading.
- Added tests for progress card calculations and calendar display logic.

feat: define theme types and preferences

- Introduced Theme and ThemePreference types for better type safety.
- Created utility functions for resolving theme based on user preference and system settings.
- Defined theme palettes for light and dark modes to ensure adequate contrast.

src/habits/routes.ts

@@ -62,6 +62,7 @@ export function createHabitRoutes(db: AppDatabase, auth: ReturnType<typeof creat
   });
   app.get('/habits/:id', c => c.json(service(c).current(id(c))));
   app.patch('/habits/:id', c => c.json(service(c).edit(id(c), body(c, habitPatch))));
+  app.delete('/habits/:id/permanent', c => { service(c).permanentlyDelete(id(c)); return c.body(null, 204); });
   app.delete('/habits/:id', c => { service(c).edit(id(c), { archived: true }); return c.body(null, 204); });
   app.get('/habits/:id/history', c => c.json({ revisions: service(c).history(id(c)) }));
   app.get('/habits/:id/tasks', c => c.json({ tasks: service(c).tasks(id(c)) }));